1. Chapter 2 at a Glance
Simplification and Approximation questions test both mathematical accuracy and calculation speed. The strongest approach is not to memorise isolated tricks, but to recognise the structure of an expression and select the shortest valid method.
Complete Chapter Flow:
BODMAS → Brackets & Vinculum → Fractions & Decimals → Powers & Roots → Cancellation & Factorisation → Calculation Shortcuts → Rounding & Approximation → Estimation & Nearest-Value Method → Mixed Problems
Exam Rule:
A shortcut is useful only when it preserves the mathematical value and follows the correct order of operations.
2. BODMAS Rule
BODMAS:
B = Brackets
O = Orders — Powers and Roots
D/M = Division and Multiplication
A/S = Addition and Subtraction
Very Important:
Division does not automatically come before multiplication.
At the same level, division and multiplication are performed from left to right.
Also Remember:
Addition does not automatically come before subtraction.
Addition and subtraction have equal priority and are performed from left to right.
Example:
36÷3×2
=12×2
=24.
3. Use of “Of”
In competitive-exam arithmetic, “of” represents multiplication.
Basic Meaning:
3/4 of 80 = 3/4 × 80 = 60.
Exam Convention:
In traditional aptitude expressions where an explicit “of” forms a clearly intended multiplication block, evaluate that block carefully before combining it with surrounding division or multiplication.
4. Brackets and Nested Expressions
Fundamental Rule:
Solve the innermost grouped expression first and then move outward.
Example:
30 − [12 − {8 − (5−2)}]
5−2=3
8−3=5
12−5=7
30−7=23.
Common Trap:
Do not treat bracket shapes themselves as a universal priority rule. The true principle is innermost first.
5. Vinculum
A vinculum is a horizontal bar that groups the terms lying under it.
Key Rule:
Treat all terms under one vinculum as a single grouped expression.
Example:
20 − 8−3
8−3=5
20−5=15.
Exam Tip:
In printed papers, carefully check exactly how many terms are covered by the vinculum.
6. Minus Sign Before a Bracket
Sign Rules:
−(a+b)=−a−b
−(a−b)=−a+b
Example:
25−(8−13)
=25−(−5)
=25+5
=30.
Exam Trap:
a−(−b)=a+b.
7. Mixed Fractions
Conversion:
a b/c = (ac+b)/c
Example:
3 2/5
=(3×5+2)/5
=17/5.
Common Mistake:
Do not write 3 2/5 as (3+2)/5.
8. Addition and Subtraction of Fractions
Rule:
Fractions with unlike denominators require a common denominator.
Example:
5/6−1/4
=10/12−3/12
=7/12.
Fast Method:
a/b ± c/d = (ad ± bc)/bd
when cross-multiplication is convenient.
9. Multiplication and Division of Fractions
Multiplication:
a/b × c/d = ac/bd
Division:
a/b ÷ c/d = a/b × d/c
Golden Shortcut:
Cancel common factors before multiplication.
Exam Trap:
In fraction division, invert only the divisor.
10. Cancellation Rule
Most Important Rule:
Cancellation occurs between factors, not between terms joined by + or −.
Example:
18/35 × 14/27
18/27=2/3
14/35=2/5
Answer=4/15.
Wrong Thinking:
You cannot cancel a number from only one term of an addition expression.
11. Decimal Addition and Subtraction
Rule:
Align numbers according to the decimal point, not according to their final digits.
Example:
12.5 + 3.075 − 0.62
=12.500 + 3.075 − 0.620
=14.955.
12. Decimal Multiplication
Rule:
Multiply as integers first and then place the decimal according to the total number of decimal places.
Example:
0.24×0.5
=0.120
=0.12.
13. Decimal Division
Rule:
Shift the decimal point in both dividend and divisor by the same number of places until the divisor becomes an integer.
Example:
6.24÷0.8
=62.4÷8
=7.8.
14. Important Fraction-Decimal Equivalents
| Fraction | Decimal | Fraction | Decimal |
| 1/2 | 0.5 | 1/8 | 0.125 |
| 1/4 | 0.25 | 3/8 | 0.375 |
| 3/4 | 0.75 | 5/8 | 0.625 |
| 1/5 | 0.2 | 7/8 | 0.875 |
| 2/5 | 0.4 | 1/10 | 0.1 |
| 3/5 | 0.6 | 1/20 | 0.05 |
| 4/5 | 0.8 | 1/25 | 0.04 |
Exam Shortcut:
These conversions should become mental calculations.
15. Useful Decimal Shortcuts
Remember:
×0.5 = ÷2
÷0.5 = ×2
×0.25 = ÷4
÷0.25 = ×4
×0.125 = ÷8
÷0.125 = ×8
16. Exponent Laws
Core Laws:
am×an=am+n
am÷an=am−n, a≠0
(am)n=amn
(ab)n=anbn
a0=1, a≠0
a−n=1/an
Exam Trap:
A negative exponent means reciprocal; it does not automatically mean a negative value.
17. Negative Bases and Brackets
Important Difference:
(−3)2=9
but
−32=−9
Never Forget:
The brackets change the mathematical meaning.
18. Square Roots
Important Relation:
For real a:
√(a2)=|a|
Example:
√144=12
√625=25.
Common Trap:
√(a+b) is generally not equal to √a+√b.
19. Simplifying Square Roots
Method:
Extract the largest perfect-square factor.
Example:
√72
=√(36×2)
=6√2.
Example:
√200
=√(100×2)
=10√2.
20. Like Radicals
Example:
√50+√8
=5√2+2√2
=7√2.
Rule:
Only radicals having the same radical part can be directly combined.
21. Cube Roots
Relation:
∛(a3)=a
Examples:
∛216=6
∛(−125)=−5.
Observation:
Real cube roots are also defined for negative numbers.
22. Perfect-Square and Perfect-Cube Factors
Useful Perfect Squares:
4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256, 289, 324, 361, 400, 625, 900
Useful Perfect Cubes:
1, 8, 27, 64, 125, 216, 343, 512, 729, 1000, 1728, 3375, 8000
23. Difference of Squares
Identity:
a2−b2=(a−b)(a+b)
Example:
582−422
=(58−42)(58+42)
=16×100
=1600.
Exam Shortcut:
Do not calculate the two squares separately when this identity applies.
24. Numbers Equally Spaced from a Convenient Base
Pattern:
(a−b)(a+b)=a2−b2
Example:
103×97
=(100+3)(100−3)
=10000−9
=9991.
Example:
48×52
=502−22
=2496.
25. Common-Factor Shortcut
Identity:
ab+ac=a(b+c)
Example:
37×48+37×52
=37(48+52)
=37×100
=3700.
26. Multiplication by 5, 25 and 125
Fast Conversions:
×5 = ×10÷2
×25 = ×100÷4
×125 = ×1000÷8
Examples:
48×25=1200
64×125=8000.
27. Division by 5, 25 and 125
Fast Conversions:
÷5 = ×2÷10
÷25 = ×4÷100
÷125 = ×8÷1000
Example:
875÷25
=875×4÷100
=35.
28. Multiplication by 9, 99 and 999
Patterns:
9=10−1
99=100−1
999=1000−1
Example:
47×99
=4700−47
=4653.
Example:
83×999
=83000−83
=82917.
29. Multiplication by 11
Example:
43×11
→ 4 (4+3) 3
=473.
Carry Case:
78×11=858, because 7+8=15 and the carry must be handled.
30. Square of a Number Ending in 5
Shortcut:
For a number ending in 5:
Multiply the preceding part n by n+1 and append 25.
Examples:
752: 7×8=56 → 5625
1152: 11×12=132 → 13225
31. Squares Near 100
Identities:
(a+b)2=a2+2ab+b2
(a−b)2=a2−2ab+b2
Example:
982
=(100−2)2
=10000−400+4
=9604.
32. Doubling and Halving
Property:
a×b=(2a)×(b/2)
Example:
25×48
=50×24
=100×12
=1200.
33. Telescoping Products
Example:
(1−1/2)(1−1/3)...(1−1/10)
=1/2×2/3×3/4×...×9/10
Intermediate factors cancel.
Answer=1/10.
Exam Shortcut:
Before multiplying a long fraction sequence, look for a cancellation chain.
34. Approximation
Approximation replaces an exact value by a convenient nearby value.
Examples:
49.92≈50
199.7≈200
3.98≈4
Exam Rule:
Approximation is useful only when the required accuracy and option gap permit it.
35. Basic Rounding Rule
Rule:
Next digit 0–4 → retain the required digit.
Next digit 5–9 → increase the required digit by 1.
Examples:
64.32 to one decimal place → 64.3
64.38 to one decimal place → 64.4
36. Rounding Whole Numbers
Examples:
467 to nearest ten → 470
6,847 to nearest hundred → 6,800
36,680 to nearest thousand → 37,000
37. Decimal Places
Rule:
Decimal places are counted immediately from the first digit after the decimal point.
Example:
12.746 to two decimal places → 12.75.
38. Significant Figures
Rules:
• Counting starts from the first non-zero digit.
• Leading zeros are not significant.
• Zeros between non-zero digits are significant.
Example:
0.004586 to 3 significant figures → 0.00459.
Exam Trap:
Do not confuse decimal places with significant figures.
39. Maximum Rounding Error
Rule:
Maximum rounding error = half of the rounding unit.
Examples:
Nearest 1 → maximum error 0.5
Nearest 10 → maximum error 5
Nearest 100 → maximum error 50
Nearest 0.1 → maximum error 0.05
40. Compatible Numbers
Compatible numbers are nearby values that make multiplication or division easy.
Example:
598÷29.9
≈600÷30
=20.
Example:
398×24.9
≈400×25
=10,000.
41. Percentage Estimation
Useful Equivalents:
50%=1/2
25%=1/4
75%=3/4
20%=1/5
12.5%=1/8
33⅓%≈1/3
Example:
24.9% of 803
≈25% of 800
=200.
42. Balanced Estimation
Example:
49.8×20.2
≈50×20
=1000.
Observation:
One factor is rounded upward and the other downward, so some of the estimation error may cancel.
43. Division Estimation
Important Principle:
Choose nearby numerator and denominator values that preserve the approximate ratio.
Example:
799÷39.8
≈800÷40
=20.
Exam Trap:
A small change in the denominator can significantly change the quotient.
44. Option-Gap Analysis
Decision Rule:
Wide option gap → rough estimate may be enough.
Close options → retain more precision.
Extremely close options → exact calculation may be necessary.
Exam Tip:
Do not calculate more accurately than the options require.
45. Order-of-Magnitude Check
Example:
198×51 ≈ 200×50 = 10,000.
Therefore answers near 1,000 or 100,000 are immediately suspicious.
Final Check:
Always ask whether the final answer should be in units, tens, hundreds, thousands or another range.
46. Two-Stage Estimation
Stage 1:
Use rough compatible numbers.
Stage 2:
If two options remain possible, retain one additional digit and refine the estimate.
Example:
149.6×4.02÷19.9
≈150×4÷20
=30.
47. Exact Shortcut Before Approximation
Golden Rule:
Before rounding awkward-looking numbers, check for cancellation, factorisation or an exact identity.
Example:
(59.92−40.12)/(59.9+40.1)
=59.9−40.1
=19.8.
48. Mixed-Problem Strategy
Three-Level Method:
Level 1 — Structure: Identify brackets, powers, roots, fractions, decimals and approximation clues.
Level 2 — Simplification: Apply cancellation, identities, convenient conversions and BODMAS.
Level 3 — Verification: Check sign, magnitude and answer options.
49. Common Chapter-Wide Traps
Avoid These Errors:
• Treating D as always before M.
• Treating A as always before S.
• Solving outer brackets before inner brackets.
• Missing a vinculum.
• Forgetting sign reversal after a minus bracket.
• Cancelling terms instead of factors.
• Inverting both fractions during division.
• Misplacing decimal points.
• Confusing −a² with (−a)².
• Assuming √(a+b)=√a+√b.
• Expanding squares when factorisation is shorter.
• Approximating an exact-value question.
• Using rough estimation despite very close options.
• Forgetting BODMAS after approximation.
50. Final 30-Second Revision Formula Sheet
BODMAS:
Brackets → Orders → D/M left to right → A/S left to right
Fractions:
a/b÷c/d = a/b×d/c
Exponents:
aman=am+n
am/an=am−n
(am)n=amn
Difference of Squares:
a2−b2=(a−b)(a+b)
Fast Multipliers:
×25=×100÷4
×125=×1000÷8
×99=×100−original number
×999=×1000−original number
Ending in 5 Square:
n5² → n(n+1), then append 25
Approximation:
Check option gap → choose compatible numbers → preserve BODMAS → verify magnitude
Last Exam Reminder:
The fastest method is the shortest correct method, not simply the most complicated shortcut you remember.
51. Verified Previous-Year Questions — Part A
Chapter 2 PYQ Bank:
The following questions cover BODMAS, brackets, vinculum, fractions, decimals, powers, roots and approximation. Solutions are kept concise so that this section can be used for rapid chapter revision.
SSC CGL PYQ
BODMAS
24 September 2024 · Tier-I · Shift II
Q1. Simplify: 133 ÷ 19 × 3 − 48 × 2 ÷ 24 + 841 ÷ (45−16)
A. 46
B. 21
C. 12
D. 42
Correct Answer: A. 46
45−16=29.
133÷19×3=7×3=21.
48×2÷24=4.
841÷29=29.
Therefore:
21−4+29=46.
RRB NTPC PYQ
Nested Brackets
18 June 2026 · UG CBT-I · Shift III
Q2. Simplify: 156 ÷ [12 + {7 × (15−9) − 28}]
A. 8
B. 10
C. 6
D. 12
Correct Answer: C. 6
15−9=6.
7×6−28=42−28=14.
12+14=26.
Therefore:
156÷26=6.
SSC CHSL PYQ
Vinculum & Brackets
15 April 2021 · Tier-I · Shift III
Q3. Simplify: 45 − [36 − {29 − (25 − 7+4)}]
A. 24
B. 22
C. 26
D. 28
Correct Answer: A. 24
Vinculum first:
7+4=11.
25−11=14.
29−14=15.
36−15=21.
Therefore:
45−21=24.
SSC CGL PYQ
Fractions & Of
24 August 2021 · Tier-I · Shift II
Q4. Simplify: 7/12 ÷ (1/10 of 2/3) − 5/3 × 9/10 + 5/8 ÷ (3/4 of 2/3)
A. −4
B. 3 23/36
C. 8 1/2
D. 7 29/36
Correct Answer: C. 8 1/2
1/10 of 2/3=1/15 and 3/4 of 2/3=1/2.
Therefore:
7/12÷1/15 − 5/3×9/10 + 5/8÷1/2
=35/4 − 3/2 + 5/4
=40/4−6/4
=34/4
=17/2 = 8 1/2.
SSC CHSL PYQ
BODMAS
1 July 2024 · Tier-I · Shift I
Q5. Simplify: 3 + 28 ÷ 35 × 15 + 4 − 3 × 4
A. 26
B. 10
C. 7
D. 64
Correct Answer: C. 7
28÷35×15
=4/5×15
=12.
Also 3×4=12.
Therefore:
3+12+4−12=7.
SSC CHSL PYQ
Bracket Operations
1 July 2024 · Tier-I · Shift III
Q6. Simplify: (36÷6)÷3 + (18÷9)×4 − (12÷6)×(5÷2)
A. 10
B. 15
C. 21
D. 5
Correct Answer: D. 5
(36÷6)÷3=6÷3=2.
(18÷9)×4=2×4=8.
(12÷6)×(5÷2)=2×2.5=5.
Therefore:
2+8−5=5.
SSC CHSL PYQ
Fractions & Of
5 July 2024 · Tier-I · Shift II
Q7. Simplify:
([1/2 ÷ (3/4 of 5/6)] ÷ [1/2 ÷ 3/4 × 5/6]) + (2+2×2)/(2÷2×2)
A. 4
B. 121/25
C. 111/25
D. 75/36
Correct Answer: C. 111/25
3/4 of 5/6=5/8.
So 1/2÷5/8=4/5.
Also:
1/2÷3/4×5/6=5/9.
Thus first part:
(4/5)÷(5/9)=36/25.
Second part:
(2+4)/(1×2)=6/2=3.
Total:
36/25+3=111/25.
SSC CHSL PYQ
BODMAS & Of
2 July 2024 · Tier-I · Shift II
Q8. Simplify: (3−3×3+3÷3+3×5) × 2 of 5 + (2+2÷2+2×2−2)
A. 105
B. 102
C. 106
D. 100
Correct Answer: A. 105
First bracket:
3−9+1+15=10.
2 of 5=10.
So first part=10×10=100.
Second bracket:
2+1+4−2=5.
Total=105.
SSC CGL PYQ
Mixed Fractions
18 September 2024 · Tier-I · Shift I
Q9. Simplify: [(5 1/2 − 3 1/3) of 1 5/13 + 1 − 2 × 3 5/2 ÷ 2 3/4]
A. 0
B. 11/2
C. −2
D. 3 1/2
Correct Answer: A. 0
5 1/2−3 1/3
=11/2−10/3
=13/6.
1 5/13=18/13, so:
13/6×18/13=3.
3 5/2=11/2 and 2 3/4=11/4.
Therefore:
2×11/2÷11/4=4.
Hence:
3+1−4=0.
SSC MTS PYQ
Fractions & Of
13 September 2023 · Shift II
Q10. Simplify: (5/3 + 6/5 ÷ 18/5) of 5/12 − (5/6 ÷ 5/12) of 5/12 + 2/3 of 3/2
A. 1
B. 5/6
C. 6/5
D. 0
Correct Answer: A. 1
6/5÷18/5=1/3.
So first bracket=5/3+1/3=2.
First part=2×5/12=5/6.
5/6÷5/12=2, so second part=2×5/12=5/6.
2/3 of3/2=1.
Therefore:
5/6−5/6+1=1.
SSC MTS PYQ
Decimal BODMAS
6 September 2023 · Shift I
Q11. Simplify: 45 − 22÷2 + 12 + 70÷35 + 0.4÷0.8 + 1.5÷3 + 1
A. 50
B. 50.5
C. 48.5
D. 54.5
Correct Answer: A. 50
22÷2=11
70÷35=2
0.4÷0.8=0.5
1.5÷3=0.5.
Therefore:
45−11+12+2+0.5+0.5+1
=50.
SSC MTS PYQ
Surds & Mixed Fractions
8 September 2023 · Shift II
Q12. Simplify:
[24√45 − 16√20 + √245 − 47√5] ÷ [3 1/5 + 1 2/5 − 2 1/6 − 2 1/5 − 5 2/5 + 3 1/6]
A. 0
B. 3
C. 1
D. 2
Correct Answer: A. 0
√45=3√5, √20=2√5 and √245=7√5.
Numerator:
72√5−32√5+7√5−47√5=0.
The denominator simplifies to −2, which is non-zero.
Therefore:
0÷(−2)=0.
SSC MTS PYQ
Square Root
3 May 2023 · Shift II
Q13. Find the value of √[((132−82)×5)+4].
A. 23
B. 26
C. 24
D. 22
Correct Answer: A. 23
13²−8²
=169−64
=105.
105×5+4=529.
Therefore:
√529=23.
RRB Group D PYQ
Square Root of Decimal
30 August 2022 · Shift III
Q14. Find the value of √1.0201.
A. 10.1
B. 101
C. 1.01
D. 1.02
Correct Answer: C. 1.01
1.0201=10201/10000.
101²=10201 and 100²=10000.
Therefore:
√1.0201=101/100=1.01.
RRB NTPC PYQ
Cube Root
26 July 2021 · CBT-I · Shift I
Q15. Between which two consecutive integers does ∛150 lie?
A. 6 and 7
B. 4 and 5
C. 7 and 8
D. 5 and 6
Correct Answer: D. 5 and 6
5³=125 and 6³=216.
Since:
125<150<216,
therefore:
5<∛150<6.
So ∛150 lies between 5 and 6.
SSC MTS PYQ
Powers
22 July 2022 · Shift I
Q16. Find the missing value: 2 × 324 × ? = 92 × 222 × 6
A. 359
B. 364
C. 363
D. 366
Correct Answer: C. 363
?=(9²×22²×6)/(2×324).
Since 324=18²:
9²/18²=1/4.
Therefore:
?=(22²×6)/(4×2)
=484×6/8
=484×3/4
=363.
RRB Group D PYQ
Exponent Laws
8 December 2025 · Shift III
Q17. Simplify:
[821 ÷ 428 × 25] ÷ [(414)1/7 × 82]
A. 2
B. 4
C. 8
D. 16
Correct Answer: B. 4
Write everything with base 2:
821=263, 428=256.
(414)1/7=24 and 8²=26.
Therefore:
263−56+5−4−6
=2²
=4.
RRB Group D PYQ
Exponent Factorisation
1 December 2025 · Shift I
Q18. Simplify: [53x+4 + 125x+1] ÷ [125x+1 − 53x+2]
A. 8
B. 7.5
C. 5
D. 10
Correct Answer: B. 7.5
125x+1=53x+3.
Take 53x+2 common from numerator and denominator:
=[5²+5]/[5−1]
=(25+5)/4
=30/4
=7.5.
SSC MTS PYQ
Approximation
6 July 2022 · Shift III
Q19. Which option is closest to the value of 305.03 ÷ 61.09 × 11.47?
A. 57
B. 47
C. 12
D. 63
Correct Answer: A. 57
305.03÷61.09 is approximately 5.
Therefore:
5×11.47≈57.35.
The closest option is 57.
RRB Group D PYQ
Nearest-Value Approximation
5 September 2022 · Shift I
Q20. Find the closest approximate value of: 4.49 ÷ 1.49 − 3.33 × 3 + 4.49
A. −2.5
B. −4.5
C. 4.5
D. 2.5
Correct Answer: A. −2.5
4.49÷1.49≈3.01.
3.33×3=9.99.
Therefore:
3.01−9.99+4.49
≈−2.49.
Closest option=−2.5.
52. Verified Previous-Year Questions — Part B
Chapter 2 PYQ Bank — Q21 to Q40:
This section gives greater emphasis to advanced simplification, approximation, nearest-value techniques, decimal operations, powers, roots, identities and mixed calculations.
SSC CGL PYQ
Fractions & Cancellation
18 August 2021 · Tier-I · Shift III
Q21. Simplify: 441 ÷ [270 ÷ 3/7 + (17 ÷ 1/3) − (8 1/2 − 5/2)]
A. 29/75
B. 49/75
C. 39/75
D. 19/75
Correct Answer: B. 49/75
270÷3/7=630.
17÷1/3=51.
8 1/2−5/2=17/2−5/2=6.
Bracket=630+51−6=675.
Therefore:
441/675=49/75.
RRB Group D PYQ
Nearest-Value Estimation
30 September 2022 · Shift I
Q22. Find the closest approximate value of: 2.33 − 4.12 + 6.13 × 11.3
A. 106
B. 64
C. 39
D. 43
Correct Answer: B. 64
Use convenient approximations:
2.33≈2, 4.12≈4, 6.13≈6 and 11.3≈11.
Therefore:
2−4+6×11
=−2+66
=64.
RRB Group D PYQ
Compatible Numbers
26 August 2022 · Shift I
Q23. Find the closest approximate value of: 44.999 ÷ 8.998 + 23.996 ÷ 11.998 − 7.009 + 8.002 × 1.998
A. 28
B. 16
C. 20
D. 24
Correct Answer: B. 16
Approximate:
45÷9 + 24÷12 −7 +8×2
=5+2−7+16
=16.
RRB Group D PYQ
Nearest-Option Method
15 September 2022 · Shift II
Q24. Find the closest approximate value of: 17.99 − 16.02 + 19.89 × 8.19
A. 122
B. 330
C. 42
D. 162
Correct Answer: D. 162
17.99≈18, 16.02≈16, 19.89≈20 and 8.19≈8.
Therefore:
18−16+20×8
=2+160
=162.
RRB NTPC PYQ
Approximation with Powers
17 June 2022 · CBT-II Level 3 · Shift III
Q25. Find the closest approximate value of: 5.01 + (3.01 × 1.992) × 4 + 6.01 ÷ 2.03
A. 56
B. 65
C. 57
D. 52
Correct Answer: A. 56
Approximate:
5.01≈5, 3.01≈3, 1.99≈2, 6.01≈6 and 2.03≈2.
Then:
5+(3×2²)×4+6÷2
=5+48+3
=56.
RRB NTPC PYQ
Percentage Approximation
16 June 2022 · CBT-II Level 2 · Shift I
Q26. Find the closest value of ? in: 44.97% of 226 + 55.03 × 4.98 − ? = 140
A. 25
B. 237
C. 508
D. 120
Correct Answer: B. 237
44.97%≈45%, 55.03≈55 and 4.98≈5.
45% of226≈102 and 55×5=275.
So:
102+275−?≈140
?≈377−140
=237.
RRB NTPC PYQ
Identity & Approximation
8 January 2021 · CBT-I · Shift I
Q27. Find the approximate value of: (2.697+0.498)2 − (2.697−0.498)2
A. 2.00
B. 5.37
C. 2.199
D. 3.195
Correct Answer: B. 5.37
Use:
(a+b)²−(a−b)²=4ab.
=4×2.697×0.498
=5.372424.
Therefore approximate value=5.37.
RRB Group D PYQ
Decimal Approximation
30 August 2022 · Shift II
Q28. Find the closest approximate value of: 17.89 − 0.0123 + 2.21 × 3.63
A. 42
B. 15
C. 26
D. 36
Correct Answer: C. 26
2.21×3.63=8.0223.
Therefore:
17.89−0.0123+8.0223
=25.9.
Closest option=26.
RRB Group D PYQ
Roots & Approximation
22 August 2022 · Shift I
Q29. Find the closest approximate value of: (√360 + 12 ÷ 6 × 3 − √170) ÷ 2
A. 6
B. 4
C. 8
D. 5
Correct Answer: A. 6
√360≈18.97 and √170≈13.03.
12÷6×3=6.
Therefore:
(18.97+6−13.03)÷2
=11.94÷2
≈6.
RRB Group D PYQ
Roots & BODMAS
29 August 2022 · Shift III
Q30. Find the closest approximate value of: (√142 + 52 ÷ 26 × 5 − √80) × 2
A. 32
B. 30
C. 20
D. 26
Correct Answer: D. 26
√142≈11.9 and √80≈8.9.
52÷26×5=10.
Therefore:
(11.9+10−8.9)×2
=13×2
=26.
RRB Group D PYQ
Mixed Decimal Approximation
18 September 2022 · Shift II
Q31. Find the closest approximate option for: 48.9 × 3.95 − 2.97 + 17.86
A. 125
B. 140
C. 211
D. 250
Correct Answer: C. 211
The exact value is approximately 208.045.
Among the given options, 211 is the closest.
RRB Group D PYQ
BODMAS Approximation
14 September 2022 · Shift III
Q32. Find the closest approximate value of: 5.18 × 4 + 2.06 × 5 − 10 ÷ 2 + 1
A. 15
B. 40
C. 26
D. 30
Correct Answer: C. 26
Using convenient approximations:
5.18≈5 and 2.06≈2.
Then:
5×4+2×5−10÷2+1
=20+10−5+1
=26.
RRB Group D PYQ
Mixed Approximation
22 September 2022 · Shift I
Q33. Find the closest approximate value of: 104.96 + 120.96 + 103.16 − 12.89 × 2.04 + 124.93 ÷ 5.1
A. 330
B. 340
C. 328
D. 334
Correct Answer: C. 328
The expression evaluates to approximately 327.3.
Therefore the closest available option is 328.
RRB Group D PYQ
Fast Approximation
2 September 2022 · Shift I
Q34. Find the closest approximate value of: 4.98 × 2 + 1.96 × 4 − 8 ÷ 2 + 1
A. 20
B. 12
C. 18
D. 15
Correct Answer: D. 15
4.98≈5 and 1.96≈2.
Therefore:
5×2+2×4−8÷2+1
=10+8−4+1
=15.
RRB NTPC PYQ
Mixed Fractions & Cancellation
21 June 2025 · Graduate CBT-I · Shift II
Q35. Simplify: 2 2/9 × 2 2/3 × 567 + 8 3/4
A. 3372.15
B. 3364.35
C. 3368.75
D. 3347.25
Correct Answer: C. 3368.75
2 2/9=20/9, 2 2/3=8/3 and 8 3/4=35/4.
20/9×8/3×567
=20×8×21
=3360.
35/4=8.75.
Total=3368.75.
RRB Group D PYQ
Decimal BODMAS
22 December 2025 · Shift I
Q36. Simplify: 0.7 × 72 ÷ 14 + 6.25 − 8.34 × 0.15 + 5.95
A. 21.549
B. 12.526
C. 14.823
D. 14.549
Correct Answer: D. 14.549
0.7×72÷14=3.6.
8.34×0.15=1.251.
Therefore:
3.6+6.25−1.251+5.95
=15.8−1.251
=14.549.
RRB NTPC PYQ
Identity & Cancellation
7 March 2021 · CBT-I · Shift I
Q37. Simplify: (4.2×4.2 − 1.9×1.9) ÷ (2.3×6.1)
A. 3
B. 2
C. 1
D. 4
Correct Answer: C. 1
Numerator:
4.2²−1.9²
=(4.2−1.9)(4.2+1.9)
=2.3×6.1.
The denominator is also 2.3×6.1.
Therefore value=1.
RRB Group D PYQ
Balanced Approximation
20 September 2022 · Shift III
Q38. Find the closest approximate value of: 239.99 × 20.01 − 99.99 × 30.01
A. 1805
B. 1815
C. 1800
D. 1810
Correct Answer: C. 1800
239.99≈240, 20.01≈20, 99.99≈100 and 30.01≈30.
Therefore:
240×20−100×30
=4800−3000
=1800.
RRB Group D PYQ
Percentage Approximation
11 October 2022 · Shift II
Q39. Find the closest approximate value of: 20.01% of 320.002 + 121.99
A. 162
B. 186
C. 154
D. 174
Correct Answer: B. 186
20.01% of320.002 is approximately 64.
121.99≈122.
Therefore:
64+122≈186.
SSC MTS PYQ
Advanced Approximation
11 February 2026 · Shift II
Q40. Find the approximate value of:
(76.91×143.97)/(7.07×12.01) − (3.932×√195.88)/(6.93×8.031/3)
A. 145
B. 105
C. 116
D. 98
Correct Answer: C. 116
Approximate:
76.91≈77, 143.97≈144, 7.07≈7, 12.01≈12,
3.93≈4, √195.88≈14, 6.93≈7 and 8.031/3≈2.
First term:
77×144÷(7×12)=132.
Second term:
4²×14÷(7×2)=16.
Therefore:
132−16=116.
53. Practice MCQs — Batch 1
Chapter 2 Mixed Practice Bank — Q1 to Q20:
This batch combines BODMAS, brackets, fractions, decimals, powers, roots, cancellation, identities, calculation shortcuts, percentages and approximation.
Practice MCQ
Q1. Simplify: 72 ÷ 8 × 3 + 52 − 7
A. 41
B. 43
C. 45
D. 47
Correct Answer: C. 45
72÷8×3=9×3=27.
52=25.
Therefore:
27+25−7=45.
Practice MCQ
Q2. Simplify: [48 ÷ (9−3) + 23] × 2
A. 24
B. 28
C. 30
D. 32
Correct Answer: D. 32
9−3=6.
48÷6=8 and 23=8.
Bracket=8+8=16.
16×2=32.
Practice MCQ
Q3. Simplify: 3/4 of 96 + 2.5 × 8 − √121
A. 77
B. 79
C. 81
D. 83
Correct Answer: C. 81
3/4 of96=72.
2.5×8=20.
√121=11.
Therefore:
72+20−11=81.
Practice MCQ
Q4. Simplify: (1.25 + 3/4) ÷ 0.5
A. 3
B. 4
C. 5
D. 6
Correct Answer: B. 4
3/4=0.75.
1.25+0.75=2.
2÷0.5=4.
Practice MCQ
Q5. Simplify: (622−382) ÷ (62+38)
A. 20
B. 22
C. 24
D. 26
Correct Answer: C. 24
Use:
a2−b2=(a−b)(a+b).
Therefore:
(62−38)(62+38)/(62+38)
=62−38
=24.
Practice MCQ
Q6. Simplify: 84 ÷ 7 + 0.125 × 64 + ∛216
A. 24
B. 26
C. 28
D. 30
Correct Answer: B. 26
84÷7=12.
0.125=1/8, so 0.125×64=8.
∛216=6.
Total=12+8+6=26.
Practice MCQ
Q7. Find the closest approximate value of: 49.7 × 19.8 + 100.2 ÷ 5.01
A. 900
B. 1000
C. 1100
D. 1200
Correct Answer: B. 1000
49.7≈50 and 19.8≈20.
100.2≈100 and 5.01≈5.
Estimated value:
50×20+100÷5
=1000+20
=1020.
Among the given options, 1000 is the closest. The exact value is also about 1004.
Practice MCQ
Q8. Simplify: 25% of 480 + 3/5 of 150 − 32
A. 168
B. 174
C. 178
D. 182
Correct Answer: C. 178
25% of480=120.
3/5 of150=90.
Therefore:
120+90−32=178.
Practice MCQ
Q9. Simplify: 53 × 5−1 ÷ 5
A. 1
B. 5
C. 25
D. 125
Correct Answer: B. 5
53×5−1÷51
=53−1−1
=51
=5.
Practice MCQ
Q10. Simplify: √288 − √32
A. 4√2
B. 6√2
C. 8√2
D. 10√2
Correct Answer: C. 8√2
√288=√(144×2)=12√2.
√32=√(16×2)=4√2.
Therefore:
12√2−4√2=8√2.
Practice MCQ
Q11. Simplify: (2 1/2 + 1.75) × 4 − 32
A. 6
B. 8
C. 10
D. 12
Correct Answer: B. 8
2 1/2=2.5.
2.5+1.75=4.25.
4.25×4=17 and 3²=9.
17−9=8.
Practice MCQ
Q12. Simplify: 0.6 ÷ 0.15 + 2.4 × 1.25
A. 6
B. 7
C. 8
D. 9
Correct Answer: B. 7
0.6÷0.15=4.
2.4×1.25=3.
Therefore:
4+3=7.
Practice MCQ
Q13. Find the value of: 47 × 99 + 16 × 125
A. 6553
B. 6603
C. 6653
D. 6703
Correct Answer: C. 6653
47×99
=47×(100−1)
=4700−47
=4653.
16×125=2000.
Therefore:
4653+2000=6653.
Practice MCQ
Q14. Find the value of: 103 × 97 + 48 × 52
A. 12,387
B. 12,437
C. 12,487
D. 12,537
Correct Answer: C. 12,487
103×97
=(100+3)(100−3)
=10000−9
=9991.
48×52
=(50−2)(50+2)
=2500−4
=2496.
Total:
9991+2496=12,487.
Practice MCQ
Q15. Approximately find: 19.9% of 501 + 24.8% of 399
A. 180
B. 190
C. 200
D. 210
Correct Answer: C. 200
19.9%≈20% and 501≈500.
20% of500=100.
24.8%≈25% and 399≈400.
25% of400=100.
Approximate total=200.
Practice MCQ
Q16. Simplify: [25 + √196] ÷ ∛64
A. 10
B. 11
C. 11 1/2
D. 12
Correct Answer: C. 11 1/2
25=32.
√196=14.
∛64=4.
Therefore:
(32+14)÷4
=46/4
=23/2 = 11 1/2.
Practice MCQ
Q17. Simplify: 1/2 ÷ (3/4 of 2/3) + 5/6
A. 7/6
B. 3/2
C. 11/6
D. 13/6
Correct Answer: C. 11/6
3/4 of2/3
=3/4×2/3
=1/2.
Therefore:
1/2÷1/2=1.
1+5/6=11/6.
Practice MCQ
Q18. Simplify: (752−252) ÷ (75−25)
A. 50
B. 75
C. 100
D. 125
Correct Answer: C. 100
a²−b²=(a−b)(a+b).
Therefore:
(75−25)(75+25)/(75−25)
=75+25
=100.
Practice MCQ
Q19. Find the value of: 23 × 999 − 230 × 99
A. 187
B. 197
C. 207
D. 217
Correct Answer: C. 207
230×99=23×10×99=23×990.
Therefore:
23×999−23×990
=23(999−990)
=23×9
=207.
Practice MCQ
Q20. Find the closest approximate value of: 299.8 × 4.02 ÷ 19.9
A. 50
B. 60
C. 70
D. 80
Correct Answer: B. 60
299.8≈300, 4.02≈4 and 19.9≈20.
Therefore:
300×4÷20
=1200÷20
=60.
54. Practice MCQs — Batch 2
Chapter 2 Mixed Practice Bank — Q21 to Q40:
This batch continues the chapter-wide practice of simplification and approximation with progressively mixed exam-style calculations.
Practice MCQ
Q21. Simplify: 150 − [36 ÷ (9−3) + 42]
A. 124
B. 126
C. 128
D. 130
Correct Answer: C. 128
9−3=6, so 36÷6=6 and 42=16. The bracket is 22; hence 150−22=128.
Practice MCQ
Q22. Round 5,876 to the nearest hundred.
A. 5,800
B. 5,900
C. 6,000
D. 5,870
Correct Answer: B. 5,900
The tens digit is 7, so the hundreds digit increases from 8 to 9. Therefore 5,876 rounds to 5,900.
Practice MCQ
Q23. Round 0.006384 to three significant figures.
A. 0.00630
B. 0.00638
C. 0.00639
D. 0.00640
Correct Answer: B. 0.00638
The first three significant digits are 6, 3 and 8. The next digit is 4, so the third significant digit remains unchanged. Answer=0.00638.
Practice MCQ
Q24. Simplify: (−4)2 − 42
A. −32
B. 0
C. 16
D. 32
Correct Answer: B. 0
(−4)2=16 and 42=16. Therefore 16−16=0.
Practice MCQ
Q25. Simplify: (1 1/2 + 1 1/4) ÷ 1/2
A. 9/2
B. 5
C. 11/2
D. 6
Correct Answer: C. 11/2
1 1/2=3/2 and 1 1/4=5/4. Their sum is 11/4. Dividing by 1/2 gives 11/4×2=11/2.
Practice MCQ
Q26. Simplify: √98 + √8
A. 7√2
B. 8√2
C. 9√2
D. 10√2
Correct Answer: C. 9√2
√98=7√2 and √8=2√2. Hence 7√2+2√2=9√2.
Practice MCQ
Q27. Find the value of ∛343.
A. 5
B. 6
C. 7
D. 8
Correct Answer: C. 7
Since 73=343, ∛343=7.
Practice MCQ
Q28. Find the value of 84 × 25.
A. 2,000
B. 2,050
C. 2,100
D. 2,200
Correct Answer: C. 2,100
Use ×25=×100÷4. Thus 84×25=8400÷4=2100.
Practice MCQ
Q29. Find the value of 6,250 ÷ 125.
A. 40
B. 45
C. 50
D. 55
Correct Answer: C. 50
Use ÷125=×8÷1000. Thus 6250×8÷1000=50.
Practice MCQ
Q30. Find the value of 36 × 99.
A. 3,464
B. 3,564
C. 3,664
D. 3,764
Correct Answer: B. 3,564
36×99=36×(100−1)=3600−36=3564.
Practice MCQ
Q31. Find the value of 852.
A. 7,125
B. 7,225
C. 7,325
D. 7,425
Correct Answer: B. 7,225
Multiply 8×9=72 and append 25. Thus 852=7225.
Practice MCQ
Q32. Find the value of 98 × 102.
A. 9,896
B. 9,996
C. 10,004
D. 10,096
Correct Answer: B. 9,996
(100−2)(100+2)=1002−22=10000−4=9996.
Practice MCQ
Q33. Find the value of (1−1/2)(1−1/3)(1−1/4)...(1−1/12).
A. 1/10
B. 1/11
C. 1/12
D. 1/13
Correct Answer: C. 1/12
The product becomes 1/2×2/3×3/4×...×11/12. Intermediate factors cancel, leaving 1/12.
Practice MCQ
Q34. Find the closest approximate value of 79.8 × 12.1.
A. 900
B. 960
C. 1,000
D. 1,080
Correct Answer: B. 960
79.8≈80 and 12.1≈12. Therefore 80×12=960.
Practice MCQ
Q35. Approximately find: 24.9% of 803 + 50.1% of 198.
A. 250
B. 275
C. 300
D. 325
Correct Answer: C. 300
24.9%≈25% of 800=200 and 50.1%≈50% of 200=100. Total≈300.
Practice MCQ
Q36. If 3.5 × 8 + ? ÷ 2 = 40, find ?.
A. 20
B. 22
C. 24
D. 26
Correct Answer: C. 24
3.5×8=28. Thus ?÷2=12, so ?=24.
Practice MCQ
Q37. Simplify: 0.75 × 48 + 2.4 ÷ 0.6 − 1.25 × 8
A. 28
B. 30
C. 32
D. 34
Correct Answer: B. 30
0.75×48=36, 2.4÷0.6=4 and 1.25×8=10. Therefore 36+4−10=30.
Practice MCQ
Q38. Simplify: 27 × 46 + 27 × 54
A. 2,600
B. 2,650
C. 2,700
D. 2,750
Correct Answer: C. 2,700
Take 27 common: 27(46+54)=27×100=2700.
Practice MCQ
Q39. Simplify: 27 × 2−3 ÷ 22
A. 2
B. 4
C. 8
D. 16
Correct Answer: B. 4
27−3−2=22=4.
Practice MCQ
Q40. Simplify: 96 ÷ 8 × 3 − 42 + 5
A. 21
B. 23
C. 25
D. 27
Correct Answer: C. 25
96÷8×3=36 and 4²=16. Therefore 36−16+5=25.
55. Practice MCQs — Batch 3
Chapter 2 Mixed Practice Bank — Q41 to Q60:
This batch combines exact simplification, roots, identities, calculation shortcuts, rounding and approximation.
Practice MCQ
Q41. Simplify: [64 ÷ (12−4) + √144] × 3
A. 54
B. 57
C. 60
D. 63
Correct Answer: C. 60
12−4=8, 64÷8=8 and √144=12. Thus (8+12)×3=60.
Practice MCQ
Q42. Simplify: 7/8 of 160 − 0.25 × 80
A. 110
B. 120
C. 130
D. 140
Correct Answer: B. 120
7/8 of160=140 and 0.25×80=20. Hence 120.
Practice MCQ
Q43. Simplify: (2.75 + 1 1/4) ÷ 0.8
A. 4
B. 5
C. 6
D. 7
Correct Answer: B. 5
1 1/4=1.25. Thus (2.75+1.25)÷0.8=4÷0.8=5.
Practice MCQ
Q44. Simplify: √324 + ∛512 − 24
A. 8
B. 10
C. 12
D. 14
Correct Answer: B. 10
18+8−16=10.
Practice MCQ
Q45. Simplify: (732−272) ÷ (73−27)
A. 90
B. 95
C. 100
D. 105
Correct Answer: C. 100
Using difference of squares, the value is 73+27=100.
Practice MCQ
Q46. Simplify: 96 × 125 ÷ 12
A. 800
B. 900
C. 1,000
D. 1,100
Correct Answer: C. 1,000
96×125=12,000 and 12,000÷12=1000.
Practice MCQ
Q47. Find the value of 999 × 54 − 99 × 540.
A. 468
B. 486
C. 504
D. 522
Correct Answer: B. 486
53,946−53,460=486.
Practice MCQ
Q48. Find the value of 1252.
A. 15,225
B. 15,425
C. 15,625
D. 15,825
Correct Answer: C. 15,625
12×13=156; append 25 → 15,625.
Practice MCQ
Q49. Find the value of 49 × 51 + 99 × 101.
A. 12,398
B. 12,448
C. 12,498
D. 12,548
Correct Answer: C. 12,498
49×51=2499 and 99×101=9999. Total=12,498.
Practice MCQ
Q50. Find the closest approximate value of: 398.7 ÷ 19.9 + 24.9 × 8.1
A. 200
B. 220
C. 240
D. 260
Correct Answer: B. 220
≈400÷20+25×8=20+200=220.
Practice MCQ
Q51. Round 0.04764 to three significant figures.
A. 0.0475
B. 0.0476
C. 0.0477
D. 0.0480
Correct Answer: B. 0.0476
The next digit after 4, 7 and 6 is 4, so the result is 0.0476.
Practice MCQ
Q52. Round −18.67 to one decimal place.
A. −18.6
B. −18.7
C. −18.8
D. −19.0
Correct Answer: B. −18.7
The hundredths digit is 7, so −18.67 rounds to −18.7.
Practice MCQ
Q53. Simplify: (1/3 + 0.5) × 12
A. 8
B. 9
C. 10
D. 11
Correct Answer: C. 10
1/3+1/2=5/6; 5/6×12=10.
Practice MCQ
Q54. Simplify: 43 ÷ 24 + √81
A. 11
B. 12
C. 13
D. 14
Correct Answer: C. 13
64÷16+9=4+9=13.
Practice MCQ
Q55. Simplify: √75 − √27
A. √3
B. 2√3
C. 3√3
D. 4√3
Correct Answer: B. 2√3
5√3−3√3=2√3.
Practice MCQ
Q56. Simplify: ∛(−216) + (−3)2
A. −15
B. −3
C. 3
D. 15
Correct Answer: C. 3
−6+9=3.
Practice MCQ
Q57. Find the value of (1−1/2)(1−1/3)...(1−1/15).
A. 1/13
B. 1/14
C. 1/15
D. 1/16
Correct Answer: C. 1/15
The telescoping product leaves 1/15.
Practice MCQ
Q58. Simplify: 37 × 62 + 37 × 38
A. 3,600
B. 3,700
C. 3,800
D. 3,900
Correct Answer: B. 3,700
37(62+38)=37×100=3700.
Practice MCQ
Q59. Find the value of 996 × 1004.
A. 999,884
B. 999,984
C. 1,000,016
D. 1,000,084
Correct Answer: B. 999,984
1000²−4²=1,000,000−16=999,984.
Practice MCQ
Q60. Approximately find: 33.2% of 601 + 12.6% of 799.
A. 250
B. 275
C. 300
D. 325
Correct Answer: C. 300
≈1/3 of600 + 1/8 of800 =200+100=300.
56. Practice MCQs — Batch 4
Chapter 2 Mixed Practice Bank — Q61 to Q80:
This batch combines fractions, decimals, exponents, roots, fast calculation, rounding and estimation.
Practice MCQ
Q61. Simplify: 144 ÷ [18 − (12−6)] + 23
A. 18
B. 20
C. 22
D. 24
Correct Answer: B. 20
18−6=12, 144÷12=12 and 2³=8. Total=20.
Practice MCQ
Q62. Simplify: 5/6 ÷ (10/9 of 3/4) + 7/8
A. 13/8
B. 15/8
C. 17/8
D. 19/8
Correct Answer: B. 15/8
10/9 of3/4=5/6. Thus the quotient is 1, and 1+7/8=15/8.
Practice MCQ
Q63. Simplify: 0.375 × 64 + 0.625 × 16
A. 30
B. 32
C. 34
D. 36
Correct Answer: C. 34
3/8×64=24 and 5/8×16=10. Total=34.
Practice MCQ
Q64. Simplify: 54 × 5−2 ÷ 25
A. 1
B. 5
C. 25
D. 125
Correct Answer: A. 1
25=5², so 54−2−2=5⁰=1.
Practice MCQ
Q65. Simplify: √0.0225 + √2.25
A. 1.55
B. 1.60
C. 1.65
D. 1.70
Correct Answer: C. 1.65
0.15+1.5=1.65.
Practice MCQ
Q66. Simplify: ∛0.008 + ∛27
A. 3.0
B. 3.1
C. 3.2
D. 3.3
Correct Answer: C. 3.2
0.2+3=3.2.
Practice MCQ
Q67. Find the value of 72 × 25 + 32 × 125.
A. 5,400
B. 5,600
C. 5,800
D. 6,000
Correct Answer: C. 5,800
1800+4000=5800.
Practice MCQ
Q68. Simplify: 8,750 ÷ 125 − 375 ÷ 25
A. 45
B. 50
C. 55
D. 60
Correct Answer: C. 55
70−15=55.
Practice MCQ
Q69. Find the value of 972.
A. 9,309
B. 9,409
C. 9,509
D. 9,609
Correct Answer: B. 9,409
(100−3)²=10000−600+9=9409.
Practice MCQ
Q70. Find the value of 1152 − 852.
A. 5,000
B. 5,500
C. 6,000
D. 6,500
Correct Answer: C. 6,000
(115−85)(115+85)=30×200=6000.
Practice MCQ
Q71. Find the closest approximate value of: 499.5 × 2.01 + 998 ÷ 49.9
A. 980
B. 1,000
C. 1,020
D. 1,040
Correct Answer: C. 1,020
≈500×2+1000÷50=1000+20=1020.
Practice MCQ
Q72. Round 12.49 to the nearest integer.
A. 11
B. 12
C. 13
D. 14
Correct Answer: B. 12
0.49<0.5, so the nearest integer is 12.
Practice MCQ
Q73. Round 68,749 to the nearest thousand.
A. 68,000
B. 68,700
C. 69,000
D. 70,000
Correct Answer: C. 69,000
The hundreds digit is 7, so round upward to 69,000.
Practice MCQ
Q74. Round 0.0008064 to three significant figures.
A. 0.000805
B. 0.000806
C. 0.000807
D. 0.000810
Correct Answer: B. 0.000806
The next digit after 8,0,6 is 4, so 0.000806.
Practice MCQ
Q75. Simplify: (49.92−30.12) ÷ (49.9+30.1)
A. 18.8
B. 19.8
C. 20.8
D. 21.8
Correct Answer: B. 19.8
The expression reduces to 49.9−30.1=19.8.
Practice MCQ
Q76. Approximately find: 19.8% of 251 + 49.9% of 302.
A. 175
B. 190
C. 200
D. 225
Correct Answer: C. 200
≈20% of250 + 50% of300 =50+150=200.
Practice MCQ
Q77. If 2.5 × 6 + ? ÷ 4 = 23, find ?.
A. 24
B. 28
C. 32
D. 36
Correct Answer: C. 32
15+?÷4=23, so ?÷4=8 and ?=32.
Practice MCQ
Q78. Simplify: 3/5 of 75 + 0.4 of 50 + 23
A. 69
B. 71
C. 73
D. 75
Correct Answer: C. 73
45+20+8=73.
Practice MCQ
Q79. Simplify: (√225 + ∛125) × 2 − 32
A. 29
B. 31
C. 33
D. 35
Correct Answer: B. 31
(15+5)×2−9=31.
Practice MCQ
Q80. Simplify: 4.8 ÷ 0.12 + 0.25 × 64
A. 52
B. 54
C. 56
D. 58
Correct Answer: C. 56
40+16=56.
57. Practice MCQs — Batch 5
Chapter 2 Mixed Practice Bank — Q81 to Q100:
This final English batch integrates the full Simplification & Approximation chapter.
Practice MCQ
Q81. Simplify: 200 − [48 ÷ {10−(6−2)} + 52]
A. 163
B. 165
C. 167
D. 169
Correct Answer: C. 167
6−2=4, 10−4=6, 48÷6=8 and 5²=25. Thus 200−33=167.
Practice MCQ
Q82. Simplify: 7/12 of 144 + 1.25 × 16 − √100
A. 90
B. 92
C. 94
D. 96
Correct Answer: C. 94
84+20−10=94.
Practice MCQ
Q83. Simplify: (3 1/3 − 1 5/6) × 6
A. 7
B. 8
C. 9
D. 10
Correct Answer: C. 9
10/3−11/6=3/2; 3/2×6=9.
Practice MCQ
Q84. Simplify: (0.875 + 1/8) × 8
A. 6
B. 7
C. 8
D. 9
Correct Answer: C. 8
0.875=7/8, so the bracket equals 1. Thus answer=8.
Practice MCQ
Q85. Simplify: 35 × 3−2 ÷ 32
A. 1
B. 3
C. 9
D. 27
Correct Answer: B. 3
35−2−2=3=3.
Practice MCQ
Q86. Simplify: √192 − √48
A. 2√3
B. 3√3
C. 4√3
D. 6√3
Correct Answer: C. 4√3
8√3−4√3=4√3.
Practice MCQ
Q87. Simplify: ∛1000 + 10√0.81
A. 17
B. 18
C. 19
D. 20
Correct Answer: C. 19
10+10×0.9=19.
Practice MCQ
Q88. Find the value of 125 × 72 − 25 × 160.
A. 4,500
B. 5,000
C. 5,500
D. 6,000
Correct Answer: B. 5,000
9000−4000=5000.
Practice MCQ
Q89. Find the value of 999 × 101.
A. 99,899
B. 100,899
C. 100,999
D. 101,899
Correct Answer: B. 100,899
999×100+999=100,899.
Practice MCQ
Q90. Find the value of 205 × 195.
A. 39,875
B. 39,925
C. 39,975
D. 40,025
Correct Answer: C. 39,975
200²−5²=40,000−25=39,975.
Practice MCQ
Q91. Find the closest approximate value of: 599.7 ÷ 29.98 + 39.9 × 24.95
A. 980
B. 1,000
C. 1,020
D. 1,040
Correct Answer: C. 1,020
≈600÷30+40×25=20+1000=1020.
Practice MCQ
Q92. Round 84,951 to the nearest hundred.
A. 84,900
B. 85,000
C. 85,100
D. 84,950
Correct Answer: B. 85,000
The tens digit is 5, so the number rounds to 85,000.
Practice MCQ
Q93. Round 8.495 to two decimal places.
A. 8.49
B. 8.50
C. 8.51
D. 8.59
Correct Answer: B. 8.50
The third decimal digit is 5, so 8.49 rounds upward to 8.50.
Practice MCQ
Q94. Round 0.009949 to three significant figures.
A. 0.00994
B. 0.00995
C. 0.00996
D. 0.0100
Correct Answer: B. 0.00995
The next digit after 9,9,4 is 9, so the result is 0.00995.
Practice MCQ
Q95. Simplify: (60.22−39.82) ÷ (60.2−39.8)
A. 90
B. 95
C. 100
D. 105
Correct Answer: C. 100
The value becomes 60.2+39.8=100.
Practice MCQ
Q96. Simplify: 12.5% of 800 + 33 1/3% of 300
A. 180
B. 190
C. 200
D. 210
Correct Answer: C. 200
1/8 of800=100 and 1/3 of300=100. Total=200.
Practice MCQ
Q97. If ? ÷ 0.25 − 12 = 28, find ?.
A. 8
B. 10
C. 12
D. 14
Correct Answer: B. 10
?÷0.25=40, so 4?=40 and ?=10.
Practice MCQ
Q98. Simplify: [23 + √144] × 3/4
A. 12
B. 15
C. 18
D. 20
Correct Answer: B. 15
(8+12)×3/4=20×3/4=15.
Practice MCQ
Q99. Find the value of (1−1/3)(1−1/4)...(1−1/10).
A. 1/10
B. 1/5
C. 2/5
D. 1/2
Correct Answer: B. 1/5
2/3×3/4×...×9/10=2/10=1/5.
Practice MCQ
Q100. Find the closest approximate value of: (79.9 × 25.1) ÷ 10.02
A. 180
B. 190
C. 200
D. 210
Correct Answer: C. 200
≈80×25÷10=200.
1. अध्याय 2 एक नज़र में
Simplification एवं Approximation questions में mathematical accuracy के साथ calculation speed भी महत्वपूर्ण होती है। सबसे अच्छा approach अलग-अलग tricks याद करना नहीं, बल्कि expression की structure पहचानकर shortest valid method चुनना है।
पूरा Chapter Flow:
BODMAS → Brackets एवं Vinculum → Fractions एवं Decimals → Powers एवं Roots → Cancellation एवं Factorisation → Calculation Shortcuts → Rounding एवं Approximation → Estimation एवं Nearest-Value Method → Mixed Problems
Exam Rule:
Shortcut तभी उपयोगी है जब वह mathematical value को सही रखे और operations का correct order follow करे।
2. BODMAS Rule
BODMAS:
B = Brackets
O = Orders — Powers एवं Roots
D/M = Division एवं Multiplication
A/S = Addition एवं Subtraction
बहुत महत्वपूर्ण:
Division हमेशा multiplication से पहले नहीं होती।
Same priority पर division और multiplication left to right solve किए जाते हैं।
इसी प्रकार:
Addition और subtraction की priority समान है तथा इन्हें left to right solve किया जाता है।
उदाहरण:
36÷3×2
=12×2
=24।
3. “Of” का प्रयोग
Basic Meaning:
3/4 of80 = 3/4×80 = 60।
Exam Convention:
Traditional aptitude expressions में स्पष्ट “of” multiplication block को carefully identify करें और surrounding operations के साथ सही क्रम में solve करें।
4. Brackets एवं Nested Expressions
मुख्य नियम:
सबसे पहले innermost grouped expression solve करें और फिर बाहर की ओर बढ़ें।
उदाहरण:
30 − [12 − {8 − (5−2)}]
5−2=3
8−3=5
12−5=7
30−7=23।
Common Trap:
Bracket के shape को independent universal priority न मानें। सही principle innermost first है।
5. Vinculum
मुख्य नियम:
एक ही vinculum के नीचे के सभी terms को एक grouped expression की तरह solve करें।
उदाहरण:
20 − 8−3
8−3=5
20−5=15।
Exam Tip:
Printed paper में ध्यान दें कि vinculum कितने terms के ऊपर है।
6. Bracket के पहले Minus Sign
Sign Rules:
−(a+b)=−a−b
−(a−b)=−a+b
उदाहरण:
25−(8−13)
=25−(−5)
=30।
Exam Trap:
a−(−b)=a+b।
7. Mixed Fractions
Conversion:
a b/c = (ac+b)/c
उदाहरण:
3 2/5
=(3×5+2)/5
=17/5।
8. Fractions का Addition एवं Subtraction
Rule:
Different denominators वाले fractions के लिए common denominator चाहिए।
उदाहरण:
5/6−1/4
=10/12−3/12
=7/12।
Fast Method:
a/b ± c/d = (ad ± bc)/bd
9. Fractions का Multiplication एवं Division
Multiplication:
a/b×c/d=ac/bd
Division:
a/b÷c/d=a/b×d/c
Golden Shortcut:
Multiplication से पहले cancellation करें।
Exam Trap:
Fraction division में केवल divisor को reciprocal में बदलें।
10. Cancellation Rule
सबसे महत्वपूर्ण:
Cancellation factors के बीच होती है, + या − से जुड़े terms के बीच नहीं।
उदाहरण:
18/35×14/27
→2/3×2/5
=4/15।
11. Decimal Addition एवं Subtraction
Rule:
Numbers को decimal point के अनुसार align करें।
उदाहरण:
12.5+3.075−0.62
=14.955।
12. Decimal Multiplication
Rule:
पहले integers की तरह multiply करें और फिर total decimal places के अनुसार decimal point लगाएँ।
उदाहरण:
0.24×0.5=0.12।
13. Decimal Division
Rule:
Dividend एवं divisor दोनों के decimal को समान places shift करके divisor को integer बनाएँ।
उदाहरण:
6.24÷0.8
=62.4÷8
=7.8।
14. महत्वपूर्ण Fraction-Decimal Equivalents
| Fraction | Decimal | Fraction | Decimal |
| 1/2 | 0.5 | 1/8 | 0.125 |
| 1/4 | 0.25 | 3/8 | 0.375 |
| 3/4 | 0.75 | 5/8 | 0.625 |
| 1/5 | 0.2 | 7/8 | 0.875 |
| 2/5 | 0.4 | 1/10 | 0.1 |
| 3/5 | 0.6 | 1/20 | 0.05 |
| 4/5 | 0.8 | 1/25 | 0.04 |
15. महत्वपूर्ण Decimal Shortcuts
याद रखें:
×0.5=÷2
÷0.5=×2
×0.25=÷4
÷0.25=×4
×0.125=÷8
÷0.125=×8
16. Exponent Laws
Core Laws:
am×an=am+n
am÷an=am−n
(am)n=amn
a0=1
a−n=1/an
Exam Trap:
Negative exponent का अर्थ reciprocal है, negative answer नहीं।
17. Negative Base और Brackets
महत्वपूर्ण अंतर:
(−3)2=9
लेकिन
−32=−9
18. Square Roots
Relation:
Real a के लिए √(a2)=|a|
Examples:
√144=12
√625=25
Exam Trap:
√(a+b) generally √a+√b नहीं होता।
19. Square Root Simplification
उदाहरण:
√72=√(36×2)=6√2
√200=√(100×2)=10√2
20. Like Radicals
उदाहरण:
√50+√8
=5√2+2√2
=7√2।
21. Cube Roots
Relation:
∛(a3)=a
Examples:
∛216=6
∛(−125)=−5
22. Important Perfect Squares एवं Cubes
Perfect Squares:
4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256, 289, 324, 361, 400, 625, 900
Perfect Cubes:
1, 8, 27, 64, 125, 216, 343, 512, 729, 1000, 1728, 3375, 8000
23. Difference of Squares
Identity:
a2−b2=(a−b)(a+b)
उदाहरण:
58²−42²
=(58−42)(58+42)
=16×100
=1600।
24. Convenient Base के आसपास Numbers
उदाहरण:
103×97
=(100+3)(100−3)
=9991।
उदाहरण:
48×52
=2500−4
=2496।
25. Common Factor
उदाहरण:
37×48+37×52
=37(48+52)
=37×100
=3700।
26. 5, 25 एवं 125 से Multiplication
Fast Conversions:
×5=×10÷2
×25=×100÷4
×125=×1000÷8
27. 5, 25 एवं 125 से Division
Fast Conversions:
÷5=×2÷10
÷25=×4÷100
÷125=×8÷1000
28. 9, 99 एवं 999 से Multiplication
Patterns:
9=10−1
99=100−1
999=1000−1
उदाहरण:
47×99=4700−47=4653।
29. 11 से Multiplication
उदाहरण:
43×11=473।
Carry Example:
78×11=858।
30. 5 पर समाप्त Number का Square
Shortcut:
5 से पहले वाले part n को n+1 से multiply करें और अंत में25 लगाएँ।
Examples:
75²=5625
115²=13225
31. 100 के पास Squares
उदाहरण:
98²
=(100−2)²
=10000−400+4
=9604।
32. Doubling और Halving
उदाहरण:
25×48
=50×24
=100×12
=1200।
33. Telescoping Products
उदाहरण:
(1−1/2)(1−1/3)...(1−1/10)
=1/2×2/3×...×9/10
=1/10।
34. Approximation
Examples:
49.92≈50
199.7≈200
3.98≈4
Exam Rule:
Approximation तभी करें जब question और option gap इसकी अनुमति दें।
35. Basic Rounding Rule
Rule:
Next digit 0–4 → retained digit unchanged।
Next digit 5–9 → retained digit में1 जोड़ें।
36. Whole Numbers का Rounding
Examples:
467 → nearest ten = 470
6,847 → nearest hundred = 6,800
36,680 → nearest thousand = 37,000
37. Decimal Places
उदाहरण:
12.746 को two decimal places तक round करने पर 12.75।
38. Significant Figures
Rule:
Counting first non-zero digit से शुरू होती है।
उदाहरण:
0.004586 को 3 significant figures तक → 0.00459।
39. Maximum Rounding Error
Rule:
Maximum rounding error = rounding unit का आधा।
Examples:
Nearest1 →0.5
Nearest10 →5
Nearest100 →50
Nearest0.1 →0.05
40. Compatible Numbers
उदाहरण:
598÷29.9
≈600÷30
=20।
उदाहरण:
398×24.9
≈400×25
=10,000।
41. Percentage Estimation
Useful Equivalents:
50%=1/2
25%=1/4
75%=3/4
20%=1/5
12.5%=1/8
उदाहरण:
24.9% of803
≈25% of800
=200।
42. Balanced Estimation
उदाहरण:
49.8×20.2
≈50×20
=1000।
43. Division Estimation
उदाहरण:
799÷39.8
≈800÷40
=20।
Exam Trap:
Denominator को बहुत aggressively round न करें।
44. Option-Gap Analysis
Decision Rule:
Options दूर हों → rough estimate।
Options close हों → अधिक precision।
Options अत्यंत close हों → exact calculation की आवश्यकता हो सकती है।
45. Order-of-Magnitude Check
उदाहरण:
198×51≈200×50=10,000।
इसलिए 1,000 या100,000 जैसा answer तुरंत suspicious होगा।
46. Two-Stage Estimation
Stage 1:
Rough compatible numbers से estimate निकालें।
Stage 2:
यदि दो options possible हों तो अधिक precision के साथ refine करें।
47. Approximation से पहले Exact Shortcut
Golden Rule:
Awkward numbers को round करने से पहले cancellation, factorisation या identity check करें।
उदाहरण:
(59.9²−40.1²)/(59.9+40.1)
=59.9−40.1
=19.8।
48. Mixed-Problem Strategy
Three-Level Method:
Level 1 — Structure: Brackets, powers, roots, fractions, decimals और approximation clues पहचानें।
Level 2 — Simplification: Cancellation, identities, conversions और BODMAS apply करें।
Level 3 — Verification: Sign, magnitude और options check करें।
49. Chapter-Wide Common Traps
इन गलतियों से बचें:
• Division को हमेशा multiplication से पहले करना।
• Addition को हमेशा subtraction से पहले करना।
• Outer bracket पहले solve करना।
• Vinculum miss करना।
• Minus bracket में signs गलत बदलना।
• Terms को cancel करना।
• Fraction division में दोनों fractions invert करना।
• Decimal point गलत place करना।
• −a² और(−a)² को समान मानना।
• √(a+b)=√a+√b मानना।
• Identity available होने पर भी squares separately calculate करना।
• Exact question को approximate करना।
• Close options में rough estimation करना।
• Approximation के बाद BODMAS भूलना।
50. Final 30-Second Revision Formula Sheet
BODMAS:
Brackets → Orders → D/M left to right → A/S left to right
Fraction Division:
a/b÷c/d=a/b×d/c
Exponent Laws:
aman=am+n
am/an=am−n
(am)n=amn
Difference of Squares:
a2−b2=(a−b)(a+b)
Fast Multipliers:
×25=×100÷4
×125=×1000÷8
×99=×100−original number
×999=×1000−original number
Ending-in-5 Square:
Preceding part × successor, फिर25 append करें।
Approximation:
Option gap देखें → compatible numbers चुनें → BODMAS रखें → magnitude verify करें।
Final Exam Reminder:
सबसे तेज method वही है जो सबसे कम steps में सही answer दे।
51. सत्यापित Previous-Year Questions — Part A
Chapter 2 PYQ Bank:
इन questions में BODMAS, brackets, vinculum, fractions, decimals, powers, roots तथा approximation का chapter-wide revision शामिल है।
SSC CGL PYQ
BODMAS
24 सितंबर 2024 · Tier-I · Shift II
प्रश्न 1. सरल कीजिए: 133 ÷ 19 × 3 − 48 × 2 ÷ 24 + 841 ÷ (45−16)
A. 46
B. 21
C. 12
D. 42
सही उत्तर: A. 46
45−16=29।
133÷19×3=7×3=21।
48×2÷24=4।
841÷29=29।
अतः:
21−4+29=46।
RRB NTPC PYQ
Nested Brackets
18 जून 2026 · UG CBT-I · Shift III
प्रश्न 2. सरल कीजिए: 156 ÷ [12 + {7 × (15−9) − 28}]
A. 8
B. 10
C. 6
D. 12
सही उत्तर: C. 6
15−9=6।
7×6−28=42−28=14।
12+14=26।
अतः:
156÷26=6।
SSC CHSL PYQ
Vinculum & Brackets
15 अप्रैल 2021 · Tier-I · Shift III
प्रश्न 3. सरल कीजिए: 45 − [36 − {29 − (25 − 7+4)}]
A. 24
B. 22
C. 26
D. 28
सही उत्तर: A. 24
सबसे पहले vinculum:
7+4=11।
25−11=14।
29−14=15।
36−15=21।
45−21=24।
SSC CGL PYQ
Fractions & Of
24 अगस्त 2021 · Tier-I · Shift II
प्रश्न 4. सरल कीजिए: 7/12 ÷ (1/10 of 2/3) − 5/3 × 9/10 + 5/8 ÷ (3/4 of 2/3)
A. −4
B. 3 23/36
C. 8 1/2
D. 7 29/36
सही उत्तर: C. 8 1/2
1/10 of2/3=1/15 तथा3/4 of2/3=1/2।
अब:
7/12÷1/15 − 5/3×9/10 + 5/8÷1/2
=35/4−3/2+5/4
=17/2
=8 1/2।
SSC CHSL PYQ
BODMAS
1 जुलाई 2024 · Tier-I · Shift I
प्रश्न 5. सरल कीजिए: 3 + 28 ÷ 35 × 15 + 4 − 3 × 4
A. 26
B. 10
C. 7
D. 64
सही उत्तर: C. 7
28÷35×15=12 तथा3×4=12।
अतः:
3+12+4−12=7।
SSC CHSL PYQ
Bracket Operations
1 जुलाई 2024 · Tier-I · Shift III
प्रश्न 6. सरल कीजिए: (36÷6)÷3 + (18÷9)×4 − (12÷6)×(5÷2)
A. 10
B. 15
C. 21
D. 5
सही उत्तर: D. 5
(36÷6)÷3=2।
(18÷9)×4=8।
(12÷6)×(5÷2)=5।
अतः:
2+8−5=5।
SSC CHSL PYQ
Fractions & Of
5 जुलाई 2024 · Tier-I · Shift II
प्रश्न 7. सरल कीजिए:
([1/2 ÷ (3/4 of 5/6)] ÷ [1/2 ÷ 3/4 × 5/6]) + (2+2×2)/(2÷2×2)
A. 4
B. 121/25
C. 111/25
D. 75/36
सही उत्तर: C. 111/25
3/4 of5/6=5/8।
1/2÷5/8=4/5।
दूसरे denominator में:
1/2÷3/4×5/6=5/9।
इसलिए first part=36/25।
Second part=(2+4)/(1×2)=3।
Total=36/25+3=111/25।
SSC CHSL PYQ
BODMAS & Of
2 जुलाई 2024 · Tier-I · Shift II
प्रश्न 8. सरल कीजिए: (3−3×3+3÷3+3×5) × 2 of 5 + (2+2÷2+2×2−2)
A. 105
B. 102
C. 106
D. 100
सही उत्तर: A. 105
पहला bracket:
3−9+1+15=10।
2 of5=10।
इसलिए first part=100।
दूसरा bracket:
2+1+4−2=5।
Total=105।
SSC CGL PYQ
Mixed Fractions
18 सितंबर 2024 · Tier-I · Shift I
प्रश्न 9. सरल कीजिए: [(5 1/2 − 3 1/3) of 1 5/13 + 1 − 2 × 3 5/2 ÷ 2 3/4]
A. 0
B. 11/2
C. −2
D. 3 1/2
सही उत्तर: A. 0
5 1/2−3 1/3=13/6।
1 5/13=18/13।
इसलिए 13/6×18/13=3।
3 5/2=11/2 तथा2 3/4=11/4।
2×11/2÷11/4=4।
अतः:
3+1−4=0।
SSC MTS PYQ
Fractions & Of
13 सितंबर 2023 · Shift II
प्रश्न 10. सरल कीजिए: (5/3 + 6/5 ÷ 18/5) of 5/12 − (5/6 ÷ 5/12) of 5/12 + 2/3 of 3/2
A. 1
B. 5/6
C. 6/5
D. 0
सही उत्तर: A. 1
6/5÷18/5=1/3।
इसलिए पहला bracket=2।
First part=5/6।
5/6÷5/12=2।
Second part=5/6।
2/3 of3/2=1।
अतः:
5/6−5/6+1=1।
SSC MTS PYQ
Decimal BODMAS
6 सितंबर 2023 · Shift I
प्रश्न 11. सरल कीजिए: 45 − 22÷2 + 12 + 70÷35 + 0.4÷0.8 + 1.5÷3 + 1
A. 50
B. 50.5
C. 48.5
D. 54.5
सही उत्तर: A. 50
22÷2=11
70÷35=2
0.4÷0.8=0.5
1.5÷3=0.5।
अतः:
45−11+12+2+0.5+0.5+1=50।
SSC MTS PYQ
Surds & Mixed Fractions
8 सितंबर 2023 · Shift II
प्रश्न 12. सरल कीजिए:
[24√45 − 16√20 + √245 − 47√5] ÷ [3 1/5 + 1 2/5 − 2 1/6 − 2 1/5 − 5 2/5 + 3 1/6]
A. 0
B. 3
C. 1
D. 2
सही उत्तर: A. 0
√45=3√5, √20=2√5 तथा√245=7√5।
Numerator:
72√5−32√5+7√5−47√5=0।
Denominator=−2।
अतः:
0÷(−2)=0।
SSC MTS PYQ
Square Root
3 मई 2023 · Shift II
प्रश्न 13. √[((132−82)×5)+4] का मान ज्ञात करें।
A. 23
B. 26
C. 24
D. 22
सही उत्तर: A. 23
13²−8²=169−64=105।
105×5+4=529।
√529=23।
RRB Group D PYQ
Square Root of Decimal
30 अगस्त 2022 · Shift III
प्रश्न 14. √1.0201 का मान ज्ञात करें।
A. 10.1
B. 101
C. 1.01
D. 1.02
सही उत्तर: C. 1.01
1.0201=10201/10000।
101²=10201 तथा100²=10000।
अतः:
√1.0201=1.01।
RRB NTPC PYQ
Cube Root
26 जुलाई 2021 · CBT-I · Shift I
प्रश्न 15. ∛150 किन दो consecutive integers के बीच स्थित है?
A. 6 और7
B. 4 और5
C. 7 और8
D. 5 और6
सही उत्तर: D. 5 और6
5³=125 तथा6³=216।
125<150<216।
इसलिए:
5<∛150<6।
अतः answer=5 और6।
SSC MTS PYQ
Powers
22 जुलाई 2022 · Shift I
प्रश्न 16. Missing value ज्ञात करें: 2 × 324 × ? = 92 × 222 × 6
A. 359
B. 364
C. 363
D. 366
सही उत्तर: C. 363
?=(9²×22²×6)/(2×324)।
324=18² और9²/18²=1/4।
अतः:
?=484×6/8
=484×3/4
=363।
RRB Group D PYQ
Exponent Laws
8 दिसंबर 2025 · Shift III
प्रश्न 17. सरल कीजिए:
[821 ÷ 428 × 25] ÷ [(414)1/7 × 82]
A. 2
B. 4
C. 8
D. 16
सही उत्तर: B. 4
सभी terms को base2 में लिखें:
821=263
428=256
(414)1/7=24
8²=26।
अतः:
263−56+5−4−6=2²=4।
RRB Group D PYQ
Exponent Factorisation
1 दिसंबर 2025 · Shift I
प्रश्न 18. सरल कीजिए: [53x+4 + 125x+1] ÷ [125x+1 − 53x+2]
A. 8
B. 7.5
C. 5
D. 10
सही उत्तर: B. 7.5
125x+1=53x+3।
Numerator एवं denominator से53x+2 common लें।
Expression:
=(5²+5)/(5−1)
=30/4
=7.5।
SSC MTS PYQ
Approximation
6 जुलाई 2022 · Shift III
प्रश्न 19. 305.03 ÷ 61.09 × 11.47 का closest approximate value कौन-सा है?
A. 57
B. 47
C. 12
D. 63
सही उत्तर: A. 57
305.03÷61.09 लगभग5 है।
इसलिए:
5×11.47≈57.35।
Nearest option=57।
RRB Group D PYQ
Nearest-Value Approximation
5 सितंबर 2022 · Shift I
प्रश्न 20. 4.49 ÷ 1.49 − 3.33 × 3 + 4.49 का closest approximate value ज्ञात करें।
A. −2.5
B. −4.5
C. 4.5
D. 2.5
सही उत्तर: A. −2.5
4.49÷1.49≈3.01।
3.33×3=9.99।
अतः:
3.01−9.99+4.49≈−2.49।
Closest option=−2.5।
52. सत्यापित Previous-Year Questions — Part B
Chapter 2 PYQ Bank — प्रश्न 21 से 40:
इस भाग में advanced simplification, approximation, nearest-value method, decimal operations, powers, roots, identities तथा mixed calculations पर अधिक focus रखा गया है।
SSC CGL PYQ
Fractions & Cancellation
18 अगस्त 2021 · Tier-I · Shift III
प्रश्न 21. सरल कीजिए: 441 ÷ [270 ÷ 3/7 + (17 ÷ 1/3) − (8 1/2 − 5/2)]
A. 29/75
B. 49/75
C. 39/75
D. 19/75
सही उत्तर: B. 49/75
270÷3/7=630।
17÷1/3=51।
8 1/2−5/2=6।
Bracket=630+51−6=675।
अतः:
441/675=49/75।
RRB Group D PYQ
Nearest-Value Estimation
30 सितंबर 2022 · Shift I
प्रश्न 22. 2.33 − 4.12 + 6.13 × 11.3 का closest approximate value ज्ञात करें।
A. 106
B. 64
C. 39
D. 43
सही उत्तर: B. 64
2.33≈2, 4.12≈4, 6.13≈6 तथा11.3≈11।
अतः:
2−4+6×11
=−2+66
=64।
RRB Group D PYQ
Compatible Numbers
26 अगस्त 2022 · Shift I
प्रश्न 23. 44.999 ÷ 8.998 + 23.996 ÷ 11.998 − 7.009 + 8.002 × 1.998 का closest approximate value ज्ञात करें।
A. 28
B. 16
C. 20
D. 24
सही उत्तर: B. 16
Approximate expression:
45÷9+24÷12−7+8×2
=5+2−7+16
=16।
RRB Group D PYQ
Nearest-Option Method
15 सितंबर 2022 · Shift II
प्रश्न 24. 17.99 − 16.02 + 19.89 × 8.19 का closest approximate value ज्ञात करें।
A. 122
B. 330
C. 42
D. 162
सही उत्तर: D. 162
17.99≈18, 16.02≈16, 19.89≈20 तथा8.19≈8।
अतः:
18−16+20×8
=2+160
=162।
RRB NTPC PYQ
Approximation with Powers
17 जून 2022 · CBT-II Level 3 · Shift III
प्रश्न 25. 5.01 + (3.01 × 1.992) × 4 + 6.01 ÷ 2.03 का closest approximate value ज्ञात करें।
A. 56
B. 65
C. 57
D. 52
सही उत्तर: A. 56
5.01≈5, 3.01≈3, 1.99≈2, 6.01≈6 तथा2.03≈2।
अब:
5+(3×2²)×4+6÷2
=5+48+3
=56।
RRB NTPC PYQ
Percentage Approximation
16 जून 2022 · CBT-II Level 2 · Shift I
प्रश्न 26. 44.97% of 226 + 55.03 × 4.98 − ? = 140 में ? का closest value ज्ञात करें।
A. 25
B. 237
C. 508
D. 120
सही उत्तर: B. 237
44.97%≈45%, 55.03≈55 तथा4.98≈5।
45% of226≈102 तथा55×5=275।
इसलिए:
102+275−?≈140
?≈237।
RRB NTPC PYQ
Identity & Approximation
8 जनवरी 2021 · CBT-I · Shift I
प्रश्न 27. (2.697+0.498)2 − (2.697−0.498)2 का approximate value ज्ञात करें।
A. 2.00
B. 5.37
C. 2.199
D. 3.195
सही उत्तर: B. 5.37
Identity:
(a+b)²−(a−b)²=4ab।
=4×2.697×0.498
=5.372424।
Approximate value=5.37।
RRB Group D PYQ
Decimal Approximation
30 अगस्त 2022 · Shift II
प्रश्न 28. 17.89 − 0.0123 + 2.21 × 3.63 का closest approximate value ज्ञात करें।
A. 42
B. 15
C. 26
D. 36
सही उत्तर: C. 26
2.21×3.63=8.0223।
17.89−0.0123+8.0223=25.9।
Closest option=26।
RRB Group D PYQ
Roots & Approximation
22 अगस्त 2022 · Shift I
प्रश्न 29. (√360 + 12 ÷ 6 × 3 − √170) ÷ 2 का closest approximate value ज्ञात करें।
A. 6
B. 4
C. 8
D. 5
सही उत्तर: A. 6
√360≈18.97 तथा√170≈13.03।
12÷6×3=6।
अतः:
(18.97+6−13.03)÷2
≈6।
RRB Group D PYQ
Roots & BODMAS
29 अगस्त 2022 · Shift III
प्रश्न 30. (√142 + 52 ÷ 26 × 5 − √80) × 2 का closest approximate value ज्ञात करें।
A. 32
B. 30
C. 20
D. 26
सही उत्तर: D. 26
√142≈11.9 तथा√80≈8.9।
52÷26×5=10।
अतः:
(11.9+10−8.9)×2
=13×2
=26।
RRB Group D PYQ
Mixed Decimal Approximation
18 सितंबर 2022 · Shift II
प्रश्न 31. 48.9 × 3.95 − 2.97 + 17.86 का closest approximate option ज्ञात करें।
A. 125
B. 140
C. 211
D. 250
सही उत्तर: C. 211
Expression का value लगभग208.045 है।
दिए गए options में 211 सबसे निकट है।
RRB Group D PYQ
BODMAS Approximation
14 सितंबर 2022 · Shift III
प्रश्न 32. 5.18 × 4 + 2.06 × 5 − 10 ÷ 2 + 1 का closest approximate value ज्ञात करें।
A. 15
B. 40
C. 26
D. 30
सही उत्तर: C. 26
5.18≈5 तथा2.06≈2।
5×4+2×5−10÷2+1
=20+10−5+1
=26।
RRB Group D PYQ
Mixed Approximation
22 सितंबर 2022 · Shift I
प्रश्न 33. 104.96 + 120.96 + 103.16 − 12.89 × 2.04 + 124.93 ÷ 5.1 का closest approximate value ज्ञात करें।
A. 330
B. 340
C. 328
D. 334
सही उत्तर: C. 328
Expression का value लगभग327.3 है।
Nearest available option=328।
RRB Group D PYQ
Fast Approximation
2 सितंबर 2022 · Shift I
प्रश्न 34. 4.98 × 2 + 1.96 × 4 − 8 ÷ 2 + 1 का closest approximate value ज्ञात करें।
A. 20
B. 12
C. 18
D. 15
सही उत्तर: D. 15
4.98≈5 तथा1.96≈2।
5×2+2×4−8÷2+1
=10+8−4+1
=15।
RRB NTPC PYQ
Mixed Fractions & Cancellation
21 जून 2025 · Graduate CBT-I · Shift II
प्रश्न 35. सरल कीजिए: 2 2/9 × 2 2/3 × 567 + 8 3/4
A. 3372.15
B. 3364.35
C. 3368.75
D. 3347.25
सही उत्तर: C. 3368.75
2 2/9=20/9, 2 2/3=8/3 तथा8 3/4=35/4।
20/9×8/3×567=3360।
35/4=8.75।
Total=3368.75।
RRB Group D PYQ
Decimal BODMAS
22 दिसंबर 2025 · Shift I
प्रश्न 36. सरल कीजिए: 0.7 × 72 ÷ 14 + 6.25 − 8.34 × 0.15 + 5.95
A. 21.549
B. 12.526
C. 14.823
D. 14.549
सही उत्तर: D. 14.549
0.7×72÷14=3.6।
8.34×0.15=1.251।
अतः:
3.6+6.25−1.251+5.95
=15.8−1.251
=14.549।
RRB NTPC PYQ
Identity & Cancellation
7 मार्च 2021 · CBT-I · Shift I
प्रश्न 37. सरल कीजिए: (4.2×4.2 − 1.9×1.9) ÷ (2.3×6.1)
A. 3
B. 2
C. 1
D. 4
सही उत्तर: C. 1
Numerator:
4.2²−1.9²
=(4.2−1.9)(4.2+1.9)
=2.3×6.1।
Denominator भी2.3×6.1 है।
अतः answer=1।
RRB Group D PYQ
Balanced Approximation
20 सितंबर 2022 · Shift III
प्रश्न 38. 239.99 × 20.01 − 99.99 × 30.01 का closest approximate value ज्ञात करें।
A. 1805
B. 1815
C. 1800
D. 1810
सही उत्तर: C. 1800
239.99≈240, 20.01≈20, 99.99≈100 तथा30.01≈30।
अतः:
240×20−100×30
=4800−3000
=1800।
RRB Group D PYQ
Percentage Approximation
11 अक्टूबर 2022 · Shift II
प्रश्न 39. 20.01% of 320.002 + 121.99 का closest approximate value ज्ञात करें।
A. 162
B. 186
C. 154
D. 174
सही उत्तर: B. 186
20.01% of320.002 लगभग64 है।
121.99≈122।
अतः:
64+122≈186।
SSC MTS PYQ
Advanced Approximation
11 फरवरी 2026 · Shift II
प्रश्न 40. Approximate value ज्ञात करें:
(76.91×143.97)/(7.07×12.01) − (3.932×√195.88)/(6.93×8.031/3)
A. 145
B. 105
C. 116
D. 98
सही उत्तर: C. 116
Approximate करें:
76.91≈77, 143.97≈144, 7.07≈7, 12.01≈12,
3.93≈4, √195.88≈14, 6.93≈7 तथा8.031/3≈2।
First term:
77×144÷(7×12)=132।
Second term:
4²×14÷(7×2)=16।
अतः:
132−16=116।
53. Practice MCQs — Batch 1
Chapter 2 Mixed Practice Bank — प्रश्न 1 से 20:
इस batch में BODMAS, brackets, fractions, decimals, powers, roots, cancellation, identities, calculation shortcuts, percentages तथा approximation का मिश्रित अभ्यास शामिल है।
Practice MCQ
प्रश्न 1. सरल कीजिए: 72 ÷ 8 × 3 + 52 − 7
A. 41
B. 43
C. 45
D. 47
सही उत्तर: C. 45
72÷8×3=9×3=27 तथा 52=25। अतः 27+25−7=45।
Practice MCQ
प्रश्न 2. सरल कीजिए: [48 ÷ (9−3) + 23] × 2
A. 24
B. 28
C. 30
D. 32
सही उत्तर: D. 32
9−3=6, 48÷6=8 और 23=8। इसलिए bracket=16 तथा 16×2=32।
Practice MCQ
प्रश्न 3. सरल कीजिए: 3/4 of 96 + 2.5 × 8 − √121
A. 77
B. 79
C. 81
D. 83
सही उत्तर: C. 81
3/4 of96=72, 2.5×8=20 तथा √121=11। अतः 72+20−11=81।
Practice MCQ
प्रश्न 4. सरल कीजिए: (1.25 + 3/4) ÷ 0.5
A. 3
B. 4
C. 5
D. 6
सही उत्तर: B. 4
3/4=0.75। इसलिए 1.25+0.75=2 और 2÷0.5=4।
Practice MCQ
प्रश्न 5. सरल कीजिए: (622−382) ÷ (62+38)
A. 20
B. 22
C. 24
D. 26
सही उत्तर: C. 24
a²−b²=(a−b)(a+b)। इसलिए expression=62−38=24।
Practice MCQ
प्रश्न 6. सरल कीजिए: 84 ÷ 7 + 0.125 × 64 + ∛216
A. 24
B. 26
C. 28
D. 30
सही उत्तर: B. 26
84÷7=12, 0.125×64=8 तथा ∛216=6। Total=26।
Practice MCQ
प्रश्न 7. 49.7 × 19.8 + 100.2 ÷ 5.01 का closest approximate value ज्ञात करें।
A. 900
B. 1000
C. 1100
D. 1200
सही उत्तर: B. 1000
49.7≈50, 19.8≈20, 100.2≈100 तथा 5.01≈5। अनुमानित value≈1020 है; दिए गए options में 1000 सबसे निकट है।
Practice MCQ
प्रश्न 8. सरल कीजिए: 25% of 480 + 3/5 of 150 − 32
A. 168
B. 174
C. 178
D. 182
सही उत्तर: C. 178
25% of480=120 तथा 3/5 of150=90। अतः 120+90−32=178।
Practice MCQ
प्रश्न 9. सरल कीजिए: 53 × 5−1 ÷ 5
A. 1
B. 5
C. 25
D. 125
सही उत्तर: B. 5
53−1−1=51=5।
Practice MCQ
प्रश्न 10. सरल कीजिए: √288 − √32
A. 4√2
B. 6√2
C. 8√2
D. 10√2
सही उत्तर: C. 8√2
√288=12√2 तथा √32=4√2। अतः difference=8√2।
Practice MCQ
प्रश्न 11. सरल कीजिए: (2 1/2 + 1.75) × 4 − 32
A. 6
B. 8
C. 10
D. 12
सही उत्तर: B. 8
2 1/2=2.5। 2.5+1.75=4.25; 4.25×4=17। फिर 17−9=8।
Practice MCQ
प्रश्न 12. सरल कीजिए: 0.6 ÷ 0.15 + 2.4 × 1.25
A. 6
B. 7
C. 8
D. 9
सही उत्तर: B. 7
0.6÷0.15=4 तथा 2.4×1.25=3। अतः answer=7।
Practice MCQ
प्रश्न 13. 47 × 99 + 16 × 125 का मान ज्ञात करें।
A. 6553
B. 6603
C. 6653
D. 6703
सही उत्तर: C. 6653
47×99=4653 तथा 16×125=2000। Total=6653।
Practice MCQ
प्रश्न 14. 103 × 97 + 48 × 52 का मान ज्ञात करें।
A. 12,387
B. 12,437
C. 12,487
D. 12,537
सही उत्तर: C. 12,487
103×97=9991 तथा 48×52=2496। Total=12,487।
Practice MCQ
प्रश्न 15. लगभग मान ज्ञात करें: 19.9% of 501 + 24.8% of 399
A. 180
B. 190
C. 200
D. 210
सही उत्तर: C. 200
19.9%≈20% of500=100 तथा 24.8%≈25% of400=100। Total≈200।
Practice MCQ
प्रश्न 16. सरल कीजिए: [25 + √196] ÷ ∛64
A. 10
B. 11
C. 11 1/2
D. 12
सही उत्तर: C. 11 1/2
32+14=46 तथा ∛64=4। इसलिए 46÷4=11 1/2।
Practice MCQ
प्रश्न 17. सरल कीजिए: 1/2 ÷ (3/4 of 2/3) + 5/6
A. 7/6
B. 3/2
C. 11/6
D. 13/6
सही उत्तर: C. 11/6
3/4 of2/3=1/2। अतः 1/2÷1/2=1 और 1+5/6=11/6।
Practice MCQ
प्रश्न 18. सरल कीजिए: (752−252) ÷ (75−25)
A. 50
B. 75
C. 100
D. 125
सही उत्तर: C. 100
Difference of squares से expression=75+25=100।
Practice MCQ
प्रश्न 19. 23 × 999 − 230 × 99 का मान ज्ञात करें।
A. 187
B. 197
C. 207
D. 217
सही उत्तर: C. 207
230×99=23×990। अतः 23(999−990)=23×9=207।
Practice MCQ
प्रश्न 20. 299.8 × 4.02 ÷ 19.9 का closest approximate value ज्ञात करें।
A. 50
B. 60
C. 70
D. 80
सही उत्तर: B. 60
299.8≈300, 4.02≈4 तथा 19.9≈20। अतः 300×4÷20=60।
54. Practice MCQs — Batch 2
Chapter 2 Mixed Practice Bank — प्रश्न 21 से 40:
इस batch में nested brackets, rounding, significant figures, exponents, roots, decimal calculations तथा approximation पर मिश्रित अभ्यास है।
Practice MCQ
प्रश्न 21. सरल कीजिए: 150 − [36 ÷ (9−3) + 42]
A. 124
B. 126
C. 128
D. 130
सही उत्तर: C. 128
9−3=6, 36÷6=6 तथा 4²=16। Bracket=22। इसलिए 150−22=128।
Practice MCQ
प्रश्न 22. 5,876 को nearest hundred तक round करें।
A. 5,800
B. 5,900
C. 6,000
D. 5,870
सही उत्तर: B. 5,900
Tens digit 7 है, इसलिए hundreds digit बढ़ेगा। Answer=5,900।
Practice MCQ
प्रश्न 23. 0.006384 को three significant figures तक round करें।
A. 0.00630
B. 0.00638
C. 0.00639
D. 0.00640
सही उत्तर: B. 0.00638
पहले three significant digits 6,3,8 हैं और next digit 4 है। इसलिए answer=0.00638।
Practice MCQ
प्रश्न 24. सरल कीजिए: (−4)2 − 42
A. −32
B. 0
C. 16
D. 32
सही उत्तर: B. 0
(−4)²=16 तथा 4²=16। अतः 16−16=0।
Practice MCQ
प्रश्न 25. सरल कीजिए: (1 1/2 + 1 1/4) ÷ 1/2
A. 9/2
B. 5
C. 11/2
D. 6
सही उत्तर: C. 11/2
3/2+5/4=11/4। अब 11/4÷1/2=11/4×2=11/2।
Practice MCQ
प्रश्न 26. सरल कीजिए: √98 + √8
A. 7√2
B. 8√2
C. 9√2
D. 10√2
सही उत्तर: C. 9√2
√98=7√2 तथा √8=2√2। Total=9√2।
Practice MCQ
प्रश्न 27. ∛343 का मान ज्ञात करें।
A. 5
B. 6
C. 7
D. 8
सही उत्तर: C. 7
7³=343। इसलिए ∛343=7।
Practice MCQ
प्रश्न 28. 84 × 25 का मान ज्ञात करें।
A. 2,000
B. 2,050
C. 2,100
D. 2,200
सही उत्तर: C. 2,100
×25=×100÷4। इसलिए 84×25=8400÷4=2100।
Practice MCQ
प्रश्न 29. 6,250 ÷ 125 का मान ज्ञात करें।
A. 40
B. 45
C. 50
D. 55
सही उत्तर: C. 50
÷125=×8÷1000। इसलिए 6250×8÷1000=50।
Practice MCQ
प्रश्न 30. 36 × 99 का मान ज्ञात करें।
A. 3,464
B. 3,564
C. 3,664
D. 3,764
सही उत्तर: B. 3,564
36×99=36×(100−1)=3600−36=3564।
Practice MCQ
प्रश्न 31. 852 का मान ज्ञात करें।
A. 7,125
B. 7,225
C. 7,325
D. 7,425
सही उत्तर: B. 7,225
8×9=72 और अंत में25 लगाएँ। उत्तर=7225।
Practice MCQ
प्रश्न 32. 98 × 102 का मान ज्ञात करें।
A. 9,896
B. 9,996
C. 10,004
D. 10,096
सही उत्तर: B. 9,996
(100−2)(100+2)=10000−4=9996।
Practice MCQ
प्रश्न 33. (1−1/2)(1−1/3)(1−1/4)...(1−1/12) का मान ज्ञात करें।
A. 1/10
B. 1/11
C. 1/12
D. 1/13
सही उत्तर: C. 1/12
यह telescoping product है। सभी intermediate factors cancel होकर 1/12 बचता है।
Practice MCQ
प्रश्न 34. 79.8 × 12.1 का closest approximate value ज्ञात करें।
A. 900
B. 960
C. 1,000
D. 1,080
सही उत्तर: B. 960
79.8≈80 तथा12.1≈12। इसलिए 80×12=960।
Practice MCQ
प्रश्न 35. लगभग मान ज्ञात करें: 24.9% of 803 + 50.1% of 198
A. 250
B. 275
C. 300
D. 325
सही उत्तर: C. 300
25% of800=200 तथा 50% of200=100। Total≈300।
Practice MCQ
प्रश्न 36. यदि 3.5 × 8 + ? ÷ 2 = 40 है, तो ? ज्ञात करें।
A. 20
B. 22
C. 24
D. 26
सही उत्तर: C. 24
3.5×8=28। इसलिए ?÷2=12 और ?=24।
Practice MCQ
प्रश्न 37. सरल कीजिए: 0.75 × 48 + 2.4 ÷ 0.6 − 1.25 × 8
A. 28
B. 30
C. 32
D. 34
सही उत्तर: B. 30
36+4−10=30।
Practice MCQ
प्रश्न 38. सरल कीजिए: 27 × 46 + 27 × 54
A. 2,600
B. 2,650
C. 2,700
D. 2,750
सही उत्तर: C. 2,700
27 common लें: 27(46+54)=27×100=2700।
Practice MCQ
प्रश्न 39. सरल कीजिए: 27 × 2−3 ÷ 22
A. 2
B. 4
C. 8
D. 16
सही उत्तर: B. 4
27−3−2=2²=4।
Practice MCQ
प्रश्न 40. सरल कीजिए: 96 ÷ 8 × 3 − 42 + 5
A. 21
B. 23
C. 25
D. 27
सही उत्तर: C. 25
96÷8×3=36 तथा4²=16। अतः 36−16+5=25।
55. Practice MCQs — Batch 3
Chapter 2 Mixed Practice Bank — प्रश्न 41 से 60:
इस batch में exact simplification, roots, identities, calculation shortcuts, rounding तथा approximation का अभ्यास है।
Practice MCQ
प्रश्न 41. सरल कीजिए: [64 ÷ (12−4) + √144] × 3
A. 54
B. 57
C. 60
D. 63
सही उत्तर: C. 60
12−4=8, 64÷8=8 तथा√144=12। अतः (8+12)×3=60।
Practice MCQ
प्रश्न 42. सरल कीजिए: 7/8 of 160 − 0.25 × 80
A. 110
B. 120
C. 130
D. 140
सही उत्तर: B. 120
7/8 of160=140 तथा0.25×80=20। Difference=120।
Practice MCQ
प्रश्न 43. सरल कीजिए: (2.75 + 1 1/4) ÷ 0.8
A. 4
B. 5
C. 6
D. 7
सही उत्तर: B. 5
1 1/4=1.25। इसलिए (2.75+1.25)÷0.8=4÷0.8=5।
Practice MCQ
प्रश्न 44. सरल कीजिए: √324 + ∛512 − 24
A. 8
B. 10
C. 12
D. 14
सही उत्तर: B. 10
18+8−16=10।
Practice MCQ
प्रश्न 45. सरल कीजिए: (732−272) ÷ (73−27)
A. 90
B. 95
C. 100
D. 105
सही उत्तर: C. 100
Difference of squares से value=73+27=100।
Practice MCQ
प्रश्न 46. सरल कीजिए: 96 × 125 ÷ 12
A. 800
B. 900
C. 1,000
D. 1,100
सही उत्तर: C. 1,000
96×125=12000 तथा12000÷12=1000।
Practice MCQ
प्रश्न 47. 999 × 54 − 99 × 540 का मान ज्ञात करें।
A. 468
B. 486
C. 504
D. 522
सही उत्तर: B. 486
999×54=53946 तथा99×540=53460। Difference=486।
Practice MCQ
प्रश्न 48. 1252 का मान ज्ञात करें।
A. 15,225
B. 15,425
C. 15,625
D. 15,825
सही उत्तर: C. 15,625
12×13=156 और अंत में25 लगाएँ। Answer=15,625।
Practice MCQ
प्रश्न 49. 49 × 51 + 99 × 101 का मान ज्ञात करें।
A. 12,398
B. 12,448
C. 12,498
D. 12,548
सही उत्तर: C. 12,498
49×51=2499 तथा99×101=9999। Total=12,498।
Practice MCQ
प्रश्न 50. 398.7 ÷ 19.9 + 24.9 × 8.1 का closest approximate value ज्ञात करें।
A. 200
B. 220
C. 240
D. 260
सही उत्तर: B. 220
लगभग 400÷20+25×8=20+200=220।
Practice MCQ
प्रश्न 51. 0.04764 को three significant figures तक round करें।
A. 0.0475
B. 0.0476
C. 0.0477
D. 0.0480
सही उत्तर: B. 0.0476
First three significant digits 4,7,6 हैं और next digit4 है। Answer=0.0476।
Practice MCQ
प्रश्न 52. −18.67 को one decimal place तक round करें।
A. −18.6
B. −18.7
C. −18.8
D. −19.0
सही उत्तर: B. −18.7
Hundredths digit7 है, इसलिए answer=−18.7।
Practice MCQ
प्रश्न 53. सरल कीजिए: (1/3 + 0.5) × 12
A. 8
B. 9
C. 10
D. 11
सही उत्तर: C. 10
1/3+1/2=5/6 और 5/6×12=10।
Practice MCQ
प्रश्न 54. सरल कीजिए: 43 ÷ 24 + √81
A. 11
B. 12
C. 13
D. 14
सही उत्तर: C. 13
64÷16+9=4+9=13।
Practice MCQ
प्रश्न 55. सरल कीजिए: √75 − √27
A. √3
B. 2√3
C. 3√3
D. 4√3
सही उत्तर: B. 2√3
√75=5√3 तथा√27=3√3। Difference=2√3।
Practice MCQ
प्रश्न 56. सरल कीजिए: ∛(−216) + (−3)2
A. −15
B. −3
C. 3
D. 15
सही उत्तर: C. 3
∛(−216)=−6 तथा(−3)²=9। इसलिए answer=3।
Practice MCQ
प्रश्न 57. (1−1/2)(1−1/3)...(1−1/15) का मान ज्ञात करें।
A. 1/13
B. 1/14
C. 1/15
D. 1/16
सही उत्तर: C. 1/15
Telescoping cancellation के बाद 1/15 बचता है।
Practice MCQ
प्रश्न 58. सरल कीजिए: 37 × 62 + 37 × 38
A. 3,600
B. 3,700
C. 3,800
D. 3,900
सही उत्तर: B. 3,700
37(62+38)=37×100=3700।
Practice MCQ
प्रश्न 59. 996 × 1004 का मान ज्ञात करें।
A. 999,884
B. 999,984
C. 1,000,016
D. 1,000,084
सही उत्तर: B. 999,984
(1000−4)(1000+4)=1000000−16=999,984।
Practice MCQ
प्रश्न 60. लगभग मान ज्ञात करें: 33.2% of 601 + 12.6% of 799
A. 250
B. 275
C. 300
D. 325
सही उत्तर: C. 300
33.2%≈1/3 of600=200 तथा12.6%≈1/8 of800=100। Total≈300।
56. Practice MCQs — Batch 4
Chapter 2 Mixed Practice Bank — प्रश्न 61 से 80:
इस batch में fractions, decimals, exponents, roots, fast calculation, rounding तथा estimation का chapter-wide अभ्यास है।
Practice MCQ
प्रश्न 61. सरल कीजिए: 144 ÷ [18 − (12−6)] + 23
A. 18
B. 20
C. 22
D. 24
सही उत्तर: B. 20
12−6=6, 18−6=12, 144÷12=12 तथा2³=8। Total=20।
Practice MCQ
प्रश्न 62. सरल कीजिए: 5/6 ÷ (10/9 of 3/4) + 7/8
A. 13/8
B. 15/8
C. 17/8
D. 19/8
सही उत्तर: B. 15/8
10/9 of3/4=5/6। इसलिए 5/6÷5/6=1 और 1+7/8=15/8।
Practice MCQ
प्रश्न 63. सरल कीजिए: 0.375 × 64 + 0.625 × 16
A. 30
B. 32
C. 34
D. 36
सही उत्तर: C. 34
0.375=3/8 और0.625=5/8। इसलिए 24+10=34।
Practice MCQ
प्रश्न 64. सरल कीजिए: 54 × 5−2 ÷ 25
A. 1
B. 5
C. 25
D. 125
सही उत्तर: A. 1
25=5²। इसलिए 54−2−2=5⁰=1।
Practice MCQ
प्रश्न 65. सरल कीजिए: √0.0225 + √2.25
A. 1.55
B. 1.60
C. 1.65
D. 1.70
सही उत्तर: C. 1.65
√0.0225=0.15 तथा√2.25=1.5। Sum=1.65।
Practice MCQ
प्रश्न 66. सरल कीजिए: ∛0.008 + ∛27
A. 3.0
B. 3.1
C. 3.2
D. 3.3
सही उत्तर: C. 3.2
∛0.008=0.2 तथा∛27=3। Total=3.2।
Practice MCQ
प्रश्न 67. 72 × 25 + 32 × 125 का मान ज्ञात करें।
A. 5,400
B. 5,600
C. 5,800
D. 6,000
सही उत्तर: C. 5,800
72×25=1800 तथा32×125=4000। Total=5800।
Practice MCQ
प्रश्न 68. सरल कीजिए: 8,750 ÷ 125 − 375 ÷ 25
A. 45
B. 50
C. 55
D. 60
सही उत्तर: C. 55
8750÷125=70 तथा375÷25=15। Difference=55।
Practice MCQ
प्रश्न 69. 972 का मान ज्ञात करें।
A. 9,309
B. 9,409
C. 9,509
D. 9,609
सही उत्तर: B. 9,409
(100−3)²=10000−600+9=9409।
Practice MCQ
प्रश्न 70. 1152 − 852 का मान ज्ञात करें।
A. 5,000
B. 5,500
C. 6,000
D. 6,500
सही उत्तर: C. 6,000
(115−85)(115+85)=30×200=6000।
Practice MCQ
प्रश्न 71. 499.5 × 2.01 + 998 ÷ 49.9 का closest approximate value ज्ञात करें।
A. 980
B. 1,000
C. 1,020
D. 1,040
सही उत्तर: C. 1,020
लगभग 500×2+1000÷50=1000+20=1020।
Practice MCQ
प्रश्न 72. 12.49 को nearest integer तक round करें।
A. 11
B. 12
C. 13
D. 14
सही उत्तर: B. 12
Decimal part 0.49 है, जो0.5 से कम है। Answer=12।
Practice MCQ
प्रश्न 73. 68,749 को nearest thousand तक round करें।
A. 68,000
B. 68,700
C. 69,000
D. 70,000
सही उत्तर: C. 69,000
Hundreds digit7 है, इसलिए answer=69,000।
Practice MCQ
प्रश्न 74. 0.0008064 को three significant figures तक round करें।
A. 0.000805
B. 0.000806
C. 0.000807
D. 0.000810
सही उत्तर: B. 0.000806
First three significant digits 8,0,6 हैं और next digit4 है। Answer=0.000806।
Practice MCQ
प्रश्न 75. सरल कीजिए: (49.92−30.12) ÷ (49.9+30.1)
A. 18.8
B. 19.8
C. 20.8
D. 21.8
सही उत्तर: B. 19.8
Difference of squares से value=49.9−30.1=19.8।
Practice MCQ
प्रश्न 76. लगभग मान ज्ञात करें: 19.8% of 251 + 49.9% of 302
A. 175
B. 190
C. 200
D. 225
सही उत्तर: C. 200
20% of250=50 तथा50% of300=150। Total≈200।
Practice MCQ
प्रश्न 77. यदि 2.5 × 6 + ? ÷ 4 = 23 है, तो ? ज्ञात करें।
A. 24
B. 28
C. 32
D. 36
सही उत्तर: C. 32
2.5×6=15। इसलिए ?÷4=8 और ?=32।
Practice MCQ
प्रश्न 78. सरल कीजिए: 3/5 of 75 + 0.4 of 50 + 23
A. 69
B. 71
C. 73
D. 75
सही उत्तर: C. 73
45+20+8=73।
Practice MCQ
प्रश्न 79. सरल कीजिए: (√225 + ∛125) × 2 − 32
A. 29
B. 31
C. 33
D. 35
सही उत्तर: B. 31
(15+5)×2−9=40−9=31।
Practice MCQ
प्रश्न 80. सरल कीजिए: 4.8 ÷ 0.12 + 0.25 × 64
A. 52
B. 54
C. 56
D. 58
सही उत्तर: C. 56
4.8÷0.12=40 तथा0.25×64=16। Total=56।
57. Practice MCQs — Batch 5
Chapter 2 Mixed Practice Bank — प्रश्न 81 से 100:
यह final batch पूरे Simplification & Approximation chapter के concepts को integrate करता है।
Practice MCQ
प्रश्न 81. सरल कीजिए: 200 − [48 ÷ {10−(6−2)} + 52]
A. 163
B. 165
C. 167
D. 169
सही उत्तर: C. 167
6−2=4, 10−4=6, 48÷6=8 तथा5²=25। इसलिए 200−33=167।
Practice MCQ
प्रश्न 82. सरल कीजिए: 7/12 of 144 + 1.25 × 16 − √100
A. 90
B. 92
C. 94
D. 96
सही उत्तर: C. 94
7/12 of144=84, 1.25×16=20 तथा√100=10। इसलिए 84+20−10=94।
Practice MCQ
प्रश्न 83. सरल कीजिए: (3 1/3 − 1 5/6) × 6
A. 7
B. 8
C. 9
D. 10
सही उत्तर: C. 9
10/3−11/6=3/2। फिर 3/2×6=9।
Practice MCQ
प्रश्न 84. सरल कीजिए: (0.875 + 1/8) × 8
A. 6
B. 7
C. 8
D. 9
सही उत्तर: C. 8
0.875=7/8। इसलिए 7/8+1/8=1 और 1×8=8।
Practice MCQ
प्रश्न 85. सरल कीजिए: 35 × 3−2 ÷ 32
A. 1
B. 3
C. 9
D. 27
सही उत्तर: B. 3
35−2−2=3¹=3।
Practice MCQ
प्रश्न 86. सरल कीजिए: √192 − √48
A. 2√3
B. 3√3
C. 4√3
D. 6√3
सही उत्तर: C. 4√3
√192=8√3 तथा√48=4√3। Difference=4√3।
Practice MCQ
प्रश्न 87. सरल कीजिए: ∛1000 + 10√0.81
A. 17
B. 18
C. 19
D. 20
सही उत्तर: C. 19
∛1000=10 तथा√0.81=0.9। इसलिए 10+10×0.9=19।
Practice MCQ
प्रश्न 88. 125 × 72 − 25 × 160 का मान ज्ञात करें।
A. 4,500
B. 5,000
C. 5,500
D. 6,000
सही उत्तर: B. 5,000
125×72=9000 तथा25×160=4000। Difference=5000।
Practice MCQ
प्रश्न 89. 999 × 101 का मान ज्ञात करें।
A. 99,899
B. 100,899
C. 100,999
D. 101,899
सही उत्तर: B. 100,899
999×101=999×100+999=99,900+999=100,899।
Practice MCQ
प्रश्न 90. 205 × 195 का मान ज्ञात करें।
A. 39,875
B. 39,925
C. 39,975
D. 40,025
सही उत्तर: C. 39,975
(200+5)(200−5)=200²−5²=40000−25=39,975।
Practice MCQ
प्रश्न 91. 599.7 ÷ 29.98 + 39.9 × 24.95 का closest approximate value ज्ञात करें।
A. 980
B. 1,000
C. 1,020
D. 1,040
सही उत्तर: C. 1,020
लगभग 600÷30+40×25=20+1000=1020।
Practice MCQ
प्रश्न 92. 84,951 को nearest hundred तक round करें।
A. 84,900
B. 85,000
C. 85,100
D. 84,950
सही उत्तर: B. 85,000
Tens digit5 है, इसलिए hundreds place round-up होगा। Answer=85,000।
Practice MCQ
प्रश्न 93. 8.495 को two decimal places तक round करें।
A. 8.49
B. 8.50
C. 8.51
D. 8.59
सही उत्तर: B. 8.50
Third decimal digit5 है। इसलिए 8.49 round-up होकर 8.50 होगा।
Practice MCQ
प्रश्न 94. 0.009949 को three significant figures तक round करें।
A. 0.00994
B. 0.00995
C. 0.00996
D. 0.0100
सही उत्तर: B. 0.00995
पहले three significant digits 9,9,4 हैं और next digit9 है। इसलिए answer=0.00995।
Practice MCQ
प्रश्न 95. सरल कीजिए: (60.22−39.82) ÷ (60.2−39.8)
A. 90
B. 95
C. 100
D. 105
सही उत्तर: C. 100
Difference of squares से value=60.2+39.8=100।
Practice MCQ
प्रश्न 96. सरल कीजिए: 12.5% of 800 + 33 1/3% of 300
A. 180
B. 190
C. 200
D. 210
सही उत्तर: C. 200
12.5%=1/8, इसलिए 800/8=100। 33 1/3%=1/3, इसलिए 300/3=100। Total=200।
Practice MCQ
प्रश्न 97. यदि ? ÷ 0.25 − 12 = 28 है, तो ? ज्ञात करें।
A. 8
B. 10
C. 12
D. 14
सही उत्तर: B. 10
?÷0.25=40। चूँकि ÷0.25=×4, इसलिए 4?=40 और ?=10।
Practice MCQ
प्रश्न 98. सरल कीजिए: [23 + √144] × 3/4
A. 12
B. 15
C. 18
D. 20
सही उत्तर: B. 15
(8+12)×3/4=20×3/4=15।
Practice MCQ
प्रश्न 99. (1−1/3)(1−1/4)...(1−1/10) का मान ज्ञात करें।
A. 1/10
B. 1/5
C. 2/5
D. 1/2
सही उत्तर: B. 1/5
2/3×3/4×...×9/10 में intermediate terms cancel होकर 2/10=1/5 बचता है।
Practice MCQ
प्रश्न 100. (79.9 × 25.1) ÷ 10.02 का closest approximate value ज्ञात करें।
A. 180
B. 190
C. 200
D. 210
सही उत्तर: C. 200
79.9≈80, 25.1≈25 तथा10.02≈10। इसलिए 80×25÷10=200।