Three identical tanks are shown above. The spheres in a given tank are the same size and packed wall-to-wall. If the tanks are filled to the top with water, then which tank would contain the most water?
say the sides of the tank are 8 (for ease)
tank one sphere volume = 4/3 pi r^3 = 4/3 pi 8 = 4/3 pi 2^3
tank 2 4/3 pi r^3 = 4/3 pi 1^3 x 8 spheres = 4/3 pi 2^3
tank3 4/3 pi r^3 = 4/3 pi 1/2^3 x 64 sphere= 4/3 pi 2^3
Looks like they will all hold the same amount of water !!!!