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SSC CPO 2020 PYQ — Question 114

SSC CPO - 25 Nov 2020 - Shift 1 • Quantitative Aptitude • Q114

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If x4 + x-4 = 194, x > 0, then what is the value of x + 1X\frac1X+ 2?

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Correct answer: A

Explanation

The correct answer is Option 1 i.e 6.

x4 + x-4 = 194

As we know,

⇒ x2 + x-2 = √(194 + 2) = √196 = 14

⇒ x + x-1 = √(14 + 2) = √16 = 4 ---- (1)

Now, according to the question

Value of  x + 1X\frac1X + 2 = 4 + 2 = 6