Question

If the ratio of the radii of two spheres is 8:9, what is the ratio of the volumes of the two spheres?

Answer 1

What is the equation for volume?

Answer 2

4/3*PI*R^2

Answer 3

close, R is cubed for a sphere.

Answer 4

oops typed it wrong

Answer 5

Alright, so the official way to do this is to declare an arbitrary factor for a base radius. We'll call this a, if you don't mind.

This makes the volume of the first sphere 4/3*PI*(a*8)^3, and the second will be 4/3*PI*(a*9)^3

Answer 6

k thanks got it !

Answer 7

You can do this, or just realize that if you divide one by the other, all common terms will drop out.

Answer 8

Excellent!