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SSC CGL 2020 PYQ — Question 65

SSC CGL - 6th March 2020 Shift 3 • Quantitative Aptitude • Q65

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If a3 + 1/a3 = 52, then the value of 2(a + 1/a) is:

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Correct answer: C

Explanation

The correct answer is option 3 i.e 8

⇒  a3 + 1/a3 = (a + 1 / a)3 - 3(a + 1 / a)

⇒ 52 = (a + 1 / a)3 - 3(a + 1 / a)

⇒ a + 1 / a = 4

⇒ 2(a + 1 / a) = 2 × 4 = 8