solid oblique cone with a slant length of 17 units is placed inside an empty cylinder with a congruent base of radius 8 units and a height of 15 units.

A solid oblique cone with a slant length of 17 units is inside an empty cylinder with a congruent base of radius 8 units and a height of 15 units.

What is the unfilled volume inside the cylinder?

320π cubic units
597π cubic units
640π cubic units
725π cubic unit