If a solid sphere of radius 10 cm is moulded into 8 spherical solid balls of equal radius, then the surface area of each ball is
- 60π cm2
- 50π cm2
- 75π cm2
- 100π cm2
The Correct Option is D
Solution and Explanation
Assume the radius of each small spherical ball be \(r\ cm\)
Volume of sphere = \(\frac{4}{3} \pi r^3\)
= \(8 × \frac{4}{3} \pi (r)^3 = \frac{4}{3} \pi (10)^3\)
\(r^3 = \frac{10^3}{8}\)
\(r = \frac{10}{2}\)
\(r = 5\ cm\)
Surface area of a sphere = \(4 \pi r^2\)
= \(4 × \pi × (5)^2\) = \(100 \pi\ cm^2\)
The correct option is (D): 100π cm2
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