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SSC CGL 2023 PYQ — Question 62

SSC CGL - 27 July 2023 - Shift 2 • Quantitative Aptitude • Q62

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Simplify the given expression.

[120×120×120−100×100×100][120×120+120×100+100×100]\frac{[120\times 120 \times 120 - 100 \times 100 \times 100]}{[120 \times 120 + 120 \times 100 + 100 \times 100]}

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Correct answer: A

Explanation

The correct answer is option 1 i.e. 20.

[120×120×120−100×100×100][120×120+120×100+100×100]\frac{[120\times 120 \times 120 - 100 \times 100 \times 100]}{[120 \times 120 + 120 \times 100 + 100 \times 100]}

⇒ (a3 - b3 = (a - b) × (a2 + ab + b2))/a2 + b2 = a2 + ab + b2

⇒ (1203 - 1003)/(1202 + 120 × 100 + 1002)

⇒ ((120 - 100)(1202 + 120 × 100 + 1002))/(1202 + 120 × 100 + 1002)

⇒ 120 - 100 = 20