Question

If the ratio of the radii of two spheres is 1 : 8, what is the ratio of the surface areas of the two spheres?

Answer 1

The surface area of a sphere is 4pi*r^2.

4pi is a constant, so we can ignore it. That means the ratio of the surface areas is determined by the radii squared.

1^2 = 1

8^2 = 64

The answer is 1:64