Discussion of Question with ID = 025 under Volume-and-Surface-Areas

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Question

A cone of height 8 cm and radius of base 16 cm is made up of modeling clay. A child reshapes it in the form of a sphere. What is the radius of the sphere?

A

8 cm.

B

10 cm.

C

6 cm.

D

12 cm.

Soln.
Ans: a

Let the radius of the sphere be R. The volumes are equal. So $4/3$ π R3 = $1/3$ π 162 × 8. Cancelling π/3 from both sides, R3 = ${16 × 16 × 8}/4$ = 512 = 83. So R = 8 cm.


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