Question

If the radius of a sphere is doubled, what is the ratio of the volume of the first sphere to that of the second sphere?

Answer 1

Let `V_1` and `V_2` be the volumes of first sphere and second sphere respectively
Radius of `1^"st"` sphere = r
`2^"nd"` sphere radius = 2r 

∴ `(Volume  1^"st")/(volume  2^"nd")=(4/3πr^3)/(4/3π(2r)^3)=1/8`