question 2 and question 3 solution required only. question 3 is related to question 2.

(2) Compute the volume of the intersection of two balls of radius R where the centre of each ball lies on the surface of the other. Use cross-sections to compute the volume. (3) Solve the problem given in the previous exercise by using cylindrical shells. (4) Let f: [a, b] - R be continuous. We write Ava,b(f) for the average of f on [a, b]. Show that