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SSC CHSL 2021 PYQ — Question 54

SSC CHSL - 15 April 2021 - Shift 2 • Quantitative Aptitude • Q54

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The sum of the radii of two circles is 286 cm and the area between the concentric cirlces is 50336 cm2. What are the radii (in cm) of the two circles? Take π=227\pi = \frac{22}{7}

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Correct answer: D

Explanation

The correct answer is option 4 i.e. 115 and 171.

Let the area of the bigger circle and the smaller circle be R cm and r cm respectively

⇒ πR2 - πr2 = 50336

⇒ R2 - r2 = 16016

⇒ (R - r)(R + r) = 16016

⇒ (R - r) = 56     ---(i)  and  (R + r) = 286   -----(ii)

Solving (i) and (ii)

R = 171 cm and r = 115cm