SarkariPYQ

SSC CGL 2019 PYQ — Question 53

SSC CGL - 13th June 2019 - Shift 1 • Quantitative Aptitude • Q53

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If     then is equal to:

Show answer & explanation

Correct answer: A

Explanation

Correct Answer is option 1 i.e. 47

Concept

Understanding

Application

Fair calculation

(x – 1/x)2 = x2 + 1/x2 – 2

Given

√x – 1/√x= √5

Squaring both sides:

x + 1/x – 2 = 5

x + 1/x = 7

Squaring again:

x2 + 1/x2 + 2 = 49

x2 + 1/x2 = 47

(√5)2 = 5