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SSC CGL 2022 PYQ — Question 71

SSC CGL - 05 Dec 2022 - Shift 4 • Quantitative Aptitude • Q71

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If x+12x=3,x +\frac{1}{2x}=3, then evaluate 8x3+1x38x^3+\frac{1}{x^3}

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Correct answer: C

Explanation

The correct answer is option 3 i.e. 180.

x+12x=3,x +\frac{1}{2x}=3,

Multiplying by 2 in the above equation

2x + 1/x = 6

Cubing on both sides

8x3 + 1/x3 = 216 - 36 = 180