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SSC CGL 2022 PYQ — Question 93

SSC CGL Tier II - Quant - 3 Feb 2022 • Quantitative Aptitude • Q93

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The value of (2.53)3+(2.47)325.3×25.3−624.91+24.7×24.7\frac{(2.53)^3+(2.47)^3}{25.3\times25.3-624.91+24.7\times24.7}is 5 x 10k, where the value of k is?

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Correct answer: A

Explanation

The correct answer is option 1 i.e. is -2

⇒ (2.53)3+(2.47)325.3×25.3−624.91+24.7×24.7\frac{(2.53)^3+(2.47)^3}{25.3\times25.3-624.91+24.7\times24.7}

As we know that,

⇒ a3 + b3 = (a + b)(a2 + b2 + ab)

 ⇒ (2.53+2.47)(2.53×2.53−6.2491+2.47×2.47)(2.53×2.53−6.2491+2.47×2.47)100\frac{(2.53+2.47)(2.53\times2.53-6.2491+2.47\times2.47)}{(2.53\times2.53-6.2491+2.47\times2.47)100}

 ⇒ 5 × 10-2 = 5 × 10k 

 k = -2