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SSC CHSL 2022 PYQ — Question 75

SSC CHSL - 26 May 2022 - Shift 2 • Quantitative Aptitude • Q75

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If (x - 1/x) = 7/3, what is the value of (x3 - 1/x3)

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Correct answer: B

Explanation

The correct answer is option 2 i.e  191927\frac{19}{27}.

Given :

(x - 1/x) = 7/3

Taking cube on both sides,

⇒ (x - 1/x)3 = 343/27

⇒ x3 - 1/x3 - 3(x × 1/x)(x - 1/x) = 343/27

⇒ x3 - 1/x3 = 343/27 + 7

⇒ x3 - 1/x3 = 532/27 = 191927\frac{19}{27}

Hence the required value is  191927\frac{19}{27}