Question

if the ratio between the radii of the two spheres is 3:5, What is the ratio of there volumes?

Answer 1

but i need the volumes?

Answer 2

Well, the volume of a sphere is 4/3*pi*r^3. So if we have 2 spheres with radii 3r and 5r, we will see that their respective volumes are 4/3*27*pi*r^3 and 4/3*125*pi*r^3. Thus the ratio of their volumes is 27:125.

Answer 3

Or Black, you also know that the ratio of volumes varies as r^3.
So:
(3)^3:(5)^3=27:125

Answer 4

I mean, they are both the same xD