Find the radius of a sphere with a volume of 36π cubic inches.

The formula for the vol. of a sphere of rad. r is   V = (4/3)*pi)*r^3.  Working backward,

                   V
r^3 =
           (4/3)*pi

Then the radius is the cube root of the above formula.

If the sphere volume is 36*pi, then:

             36*pi cubic inches
r^3 = = 27 cubic inches
             (4/3 pi)

and so                       r = cube root of 27 cubic inches)    =   3 inches (ans)

The answer is c. 7 (i think) i’m almost sure though