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SSC CPO 2023 PYQ — Question 116

SSC CPO - 04 Oct 2023 - Shift 1 • Quantitative Aptitude • Q116

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If a +1a+\frac{1}{a}= 3, then the value of a4  +1a4+\frac{1}{a^4} is:

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Correct answer: D

Explanation

The correct answer is option 4 i.e. 47.

Given that

If a +1a+\frac{1}{a}= 3

Squaring both sides

⇒ a2 + 1/a2 + 2 = 9

⇒ a2 + 1/a2  = 7

Again, Squaring both sides

⇒  a4  +1a4+\frac{1}{a^4} + 2 = 49

⇒  a4  +1a4+\frac{1}{a^4}  = 49 - 2 = 47