A sphere ball with a radius of 6 cm just fits inside a cylindrical can with a radius of 6 cm and a height of 10 cm. How much empty space is left in the can?

A cone of radius r and height h is placed inside a cylindrical can of radius r and height h.What fraction of the available volume does the cone occupy?

A hopper for storing grain is built in the shape of an inverted pyramid with a square base of edge width 5 m. The full height of the pyramid is 15 m; however, the bottom 3 m was removed to provide a means to empty the hopper. Find the volume of the hopper.