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SSC CHSL 2023 PYQ — Question 66

SSC CHSL 2023 - 02 Aug 2023 - Shift 2 • Quantitative Aptitude • Q66

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If ( a + 1a\frac{1}{a}) = 6, then what is the value of 34\frac{3}{4}(a2 + 1a2\frac{1}{a^2})?

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Correct answer: C

Explanation

The correct answer is option 3 i.e. 25.5.

Given:

 (a + 1/a) = 6

Formula used:

(a + b)2 = a2 + b2 + 2ab

Calculations:

According to the question;

⇒ (a + 1/a)2 = a2 + 1/a2 + 2

⇒ 62 = a2 + 1/a2 + 2

⇒ a2 + 1/a2 = 34

Now,

⇒ 3/4(a2 + 1/a2) = 3/4 × 34

⇒ 51/2 = 25.5