Course & TextbookCalculus Essential Calculus Early Transcendentals - Newest edition Chapter 1.1 Problem 18

Question Details:

A spherical balloon with radius r inches has volume V(r) = 4/3?(r^3). Find a function that represents the amount of air required to inflate the balloon from a radius of r inches to a radius of r+1 inches.

I gotta be dumb but I'm not certain how to carry through the cube cause I don't have the solution.