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SSC Selection Post 2023 PYQ — Question 63

SSC Selection Post - Higher Secondary Level - 28 June 2023 - Shift 2 • Quantitative Aptitude • Q63

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If x = 14, y = 15 and z = 17, then the value of x3 + y3 + z3 - 3xyz is:

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Correct answer: B

Explanation

The correct answer is Option 2 i.e. 322.

x3+y3+z3−3xyz=12(x+y+z)[(x−y)2+(y−z)2+(z−x)2]x^3 + y^3 + z^3 - 3xyz=\frac{1}{2}(x+y+z)[(x-y)^2+(y-z)^2+(z-x)^2]

=12(14+15+17)[(14−15)2+(15−17)2+(17−14)2]=\frac{1}{2}(14 + 15 + 17)[(14-15)^2+(15-17)^2+(17-14)^2]

= (1/2) × 46 × (1 + 4 + 9)

= 23 × 14

= 322