Question

A water ballon has a balloon has a diameter of 6 inches. how many cubic inches of water does it contain when it is 3/4 full

Answer 1

V = 4/3πr^3
V = 4/3π216
V = 2(216)π/3
V = 144π
Now, it's 3/4 full.
144π(3)/4
V = 108π or V ≈ 339.29

Answer 2

Find the volume of a sphere whose diameter is 6, the sphere contains that much water when it is full. So when it is 3/4 full it contains 3/4 * the volume you just calculated