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SSC CHSL 2022 PYQ — Question 54

SSC CHSL - 25 May 2022 - Shift 2 • Quantitative Aptitude • Q54

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If (x + 1x\frac{1}{x}) = 7.5, what is the value of (x2+1x2x^2+\frac{1}{x^2 })?

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Correct answer: A

Explanation

The correct answer is option 1 i.e. 54.25

We know, (a + b)2 = a2 + b2 + 2ab

Here, a = x and b = 1/x

Thus, (x + 1/x)2 = x2 + 1/x2 + 2

⇒ x2 + 1/x2 = (x + 1/x)2 - 2 

⇒ x2 + 1/x2 = 7.52 - 2 

⇒ x2 + 1/x2 = 56.25 - 2 = 54.25