Let
be the radius and height of cylinder A, and
be the radius and height of cylinder B.
We know that
. Since the diameter of cylinder B is 12, its radius is 6.
Since the diameter of cylinder B is 4 inches greater than that of cylinder A, the diameter of cylinder A is 8, which implies that its radius is 4.
The formula for the volume of a cylinder is

And we have


Which means that the volume of cylinder B is 108/48=2.25 times greater than the volume of cylinder A