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SSC CGL 2022 PYQ — Question 56

SSC CGL - 06 Dec 2022 - Shift 3 • Quantitative Aptitude • Q56

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Find the mean proportion of a3+b3a−banda2−b2a2−ab+b2\frac{a^3+b^3}{a-b} and \frac{a^2-b^2}{a^2-ab+b^2}.

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Correct answer: B

Explanation

The correct answer is option 2 i.e. a + b.

Concept used:

If x is the mean proportion of a and b then

x2 = ab                ---- (1)

Calculations:

Let the mean proportion be x.

Using equation (1), we get

⇒ x2 = [(a3 + b3)/(a - b)] × [(a - b)(a + b)/a2- ab + b2]

⇒ x2 = [(a + b)(a2- ab + b2)/(a - b)] × [(a - b)(a + b)/a2- ab + b2]

⇒ x2 = (a + b)(a + b)

⇒ x = a + b