Quantitative Aptitude
Simplification and Approximation
647 Questions
Simplification and Approximation Questions
B
Correct answer
Explanation
32.1 × 2799 ÷ 549 + 121. First, 2799 ÷ 549 ≈ 5.1 (since 549 × 5 = 2745). Then 32.1 × 5.1 ≈ 32 × 5 = 160. Finally 160 + 121 = 281. The closest option is 280.
E
Correct answer
Explanation
3544 ÷ 23 ≈ 3544 ÷ 23 = 154.08. The closest approximate value is 155 (option E). 3544/23 is exactly 154.08... so 155 is the correct approximation.
D
Correct answer
Explanation
Approximate: 89 × 14 ÷ 15 ≈ 1246 ÷ 15 ≈ 83.07. Alternatively: 89 × (14/15) ≈ 89 × 0.933 ≈ 83.06. Option D (83) is correct as it's the closest to 83.07.
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$4900$
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$4100$
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$3900$
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$5000$
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$4500$
E
Correct answer
Explanation
Rounding to convenient values: 59.899 ≈ 60, 5.002 ≈ 5, 14.989 ≈ 15. Then 60 × 5 × 15 = 300 × 15 = 4500. Option E is correct.
A
Correct answer
Explanation
Numerator: 749 - 325 - 124 = 300. Denominator: 1254 - 1100 = 154. 300 ÷ 154 ≈ 1.95, which rounds to 2. Option A is correct.
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19450
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19435
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20450
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19950
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18650
B
Correct answer
Explanation
Calculate: 16.2% of 986 ≈ 0.162 × 986 ≈ 159.7. Then 12.8% of 963 ≈ 0.128 × 963 ≈ 123.3. Multiply: 159.7 × 123.3 ≈ 19686. The closest option is 19435 (Option B). The approximation accounts for rounding in intermediate steps.
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132600
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131700
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133500
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121600
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123400
D
Correct answer
Explanation
Use difference of squares: a² - b² = (a-b)(a+b). Here: (476.25 - 324.23)(476.25 + 324.23) = (152.02)(800.48) ≈ 152 × 800.5 = 121,676. The closest option is 121600 (Option D). Small variations occur from rounding.
D
Correct answer
Explanation
Calculate step by step: 4966 ÷ 0.6 ≈ 8276.67. Then multiply by 0.5: 8276.67 × 0.5 ≈ 4138.3. The closest option is 4150 (Option D). The slight difference is due to rounding intermediate values.
C
Correct answer
Explanation
Calculate: 12.396 × 65.67 ≈ 813.5. Then add to 675.256: 675.256 + 813.5 ≈ 1488.8. The closest option is 1500 (Option C). Rounding to nearest hundred gives 1500.
A
Correct answer
Explanation
80880 ÷ 888 ÷ 8 = 91 ÷ 8 ≈ 11.37 ≈ 11. First: 80880 ÷ 888 ≈ 91 (since 888 × 91 = 80808, close to 80880). Then 91 ÷ 8 = 11.375, which rounds to approximately 11. Option A is correct.
A
Correct answer
Explanation
Round 212.005 to 212 and 71.888 to 72 for easy calculation: 212 ÷ 72 = 2.944, which rounds to 3. The approximation is valid because the dividend and divisor were adjusted in opposite directions, minimizing error.
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49000
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44000
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43000
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41000
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47000
E
Correct answer
Explanation
8758 × 350 ÷ 65 = 8758 × 350/65 ≈ 8758 × 5.3846 ≈ 47147. Rounding: 8758 ≈ 8760, 350/65 ≈ 5.4, 8760 × 5.4 ≈ 47304. Closest to 47000. Option E is correct.
B
Correct answer
Explanation
Approximate: (38.9)² ÷ 12.95 × 29 = ? - 795. 38.9² ≈ 1510. Then 1510 ÷ 13 ≈ 116. Then 116 × 29 ≈ 3364. So ? ≈ 3364 + 795 = 4159. Among options, 4200 (B) is closest. Option A is too low. Option C is too high. Option D is too high. Option E is too low.
A
Correct answer
Explanation
Use difference of squares: a² - b² = (a+b)(a-b). (97.1)² - (87.2)² = (97.1+87.2)(97.1-87.2) = (184.3)(9.9) ≈ 1824.6. Then subtract (13.01)² ≈ 169.2, giving ≈ 1655.4. Rounding to nearest 50 gives 1670. Option A is correct. Option B is slightly high. Option C is too low. Option D is too high. Option E is much too high.
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96850
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90770
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98700
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89800
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100000
E
Correct answer
Explanation
Approximating: 20300 ≈ 20000, 36.14 ≈ 36, 176.120 ≈ 176, 38.72 ≈ 39. So: (20000/36)×176 ≈ 555.56×176 ≈ 97778. Then 97778 - 39 ≈ 97739, which rounds to approximately 100000. The exact calculation: 20300÷36.14 × 176.120 - 38.72 ≈ 561.8×176.12 - 38.72 ≈ 98963 - 38.72 ≈ 98924, closest to 100000 among options.