You find the total volume :
V= pi x r^2 x h
V = 7680 pi or 24127.43 cubic centimetres
Then find the small ones
V = pi x r ^2 x h
V= 480 pi or 1507.96 cubic centimetres
Then subtract
The volume that you are searching for : 7680pi - 480 pi = 7200 pi or 22619.46 cubic centimetres