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SSC Selection Post 2023 PYQ — Question 65

SSC Selection Post - Matriculation Level - 28 June 2023 - Shift 4 • Quantitative Aptitude • Q65

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A solid iron sphere of radius 21 cm is melted down into a cone of height 84 cm. What will be the radius of the cone ?

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Correct answer: D

Explanation

The correct answer is Option 4 i.e. 21 cm

Volume of Sphere = Volume of Cone

43πr3\frac{4}{3} \pi r^3 = 13πR2h\frac{1}{3} \pi R^2 h

4r3 = R2h

4 × (21)3 = R2 × 84

(21)3 = 9261 ⇒ 4 × 9261 = 37044

R2 = 3704484\frac{37044}{84} = 441

R = 441\sqrt{441} = 21 cm