Question

the volume and surface area of a sphere are numerically the same, then its radius is

Answer 1

Let the radius be r
Surface area of sphere = 4πr^2
Volume = 4/3πr^3
Given = 4πr^2 = 4/3πr^3
Then r = 3
Hence the radius will be 3

Answer 2

volume = 4/3 pie r^3
and surface area = 4 pie r^2

so 4/3pie r^3 =4 pie r^2
r = 3