Plz help me out, this is from a study guide for my test today! thank you!

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent

Taina went to the toy store and spent $21.05 on a board game, $2.75 on coloring books, and $13.22 on a model airplane. about how much money did taina spend in the toy store?

Find the center of the circle that can be circumscribed about efg with e(4,4) f(4,2) g(8,2)