Question

The radius of a small ball is around 4.89796 cm. the radius of a basketball is about 2.45 times larger. what is the ratio of the surface areas of the small ball and a basketball?

Answer 1

Formula for surface area of a sphere of radius r is A = 4pi*r^2.

The same formula, for the case where the radius is 2.45 times greater, comes out to A = 4pi*[2.45r]^2.

Just find the ratio of

4pi*r^2 to 4pi*[2.45r]^2. It is 1/6.