The radius of the Earth is approximately 3,960 miles. Find the approximate surface-area-to-volume ratio of the Earth.

Answer 1

A=4πr^2

V=4/3πr^3

A/V = 4πr^2/(4/3πr^3)

Some of the terms cancel each other out.

4πr^2/(4/3πr^3) = 1/3r