Can you Explain to me this question :

The volume, V, and surface area, S of a sphere with radius r are given by the formulas

http://www12.0zz0.com/2009/01/11/11/734672347.jpg

Find the surface area of a sphere that has a volume = 321 cm3. (To 2 decimal places)

Find the volume of the sphere that has surface area = 400 cm2 .To 2 decimal places)