Question

A cylindrical rod, whose height is 8 times its radius, is melted and cast into spherical balls of the same radius. The total number of spherical balls, so formed, is

• A. 3
• B. 4
• C. 6
• D. 8

Answer 1

The correct option is C 6

Let the number of balls be $n$.

Given that cylindrical rod whose height is $8$ times of its radius

i.e., $h=8r$

Volume of the cylinder $=n\times$ Volume of the sphere

$\pi r^{2}h=n\times \frac{4}{3}\pi r^3$

$\pi r^2\times 8r=n\times \frac{4}{3}\pi r^3$

$n=6$

Hence, this is the answer.