Exams › SSC CGL (Prelims) › General

If x + 1/x = 5, what is the value of x^3 + 1/x^3?

1. 100
2. 110
3. 120
4. 125

Correct answer: 110

Solution

Applying x^3 + 1/x^3 = (x + 1/x)^3 - 3(x + 1/x) with the sum equal to 5 gives 125 - 15 = 110.

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