


The volume of a cylinder of radius 1 and height 1 is π r 2 h = π × 1 2 × 1. One quarter of the cylinder is 1 4 π × 1 2 × 1. The unreachable volume of the little cube is the volume of the little cube, 1 3, minus the volume that can be reached by the sphere, so the unreachable volume is 1 3 − 1 4 π × 1 2 × 1. There are three little ...