Acylindrical metal pipe has a diameter of 8.4 millimeters and a height of 10 millimeters. a hole cut out of the center has a diameter of 6 millimeters.

what is the volume of metal in the pipe? use 3.14 for π and round the answer to the nearest tenth of a cubic millim

Well, it you take the volume of the pipe, before the hole
diameter is 8.4, meaning radius is half that or 4.2, height is 10

then, you take the volume of the "cylindrical hole"
and subtract that volume from the pipe's, you'd end up with their difference,
which is, whatever is not taken up by the hole, namely, just the metal in the pipe