Solve the given problem:
Problem: An insulating sphere is 8.00 cm in diameter and carries a 6.40 µC charge uniformly distributed throughout its interior volume.
Part A: Calculate the charge enclosed by a concentric spherical surface with the following radius.
(a) r = 2.50 cm
answer in cm
(b) r = 6.00 cm
answer in muC
Please show me how work it out for above problem.