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SSC Selection Post 2020 PYQ — Question 75

SSC Selection Post - Graduation Level 2020 - 9 Nov 2020 - Shift 2 • Quantitative Aptitude • Q75

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If √x + 1x \frac{1}{\sqrt{x}} = 4, find the value of x2 + 1x2 \frac{1}{x^2}

 

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Correct answer: D

Explanation

The correct answer is Option 4 i.e. 194.

√x + 1/√x = 4

⇒ (√x + 1/√x)2 = 42

⇒ x + 2 + 1/x = 16

⇒ x + 1/x = 16 - 2 = 14:

⇒ x2 + 1/x2 = 142 - 2 = 194