MathDB
FRUSTRAted ;)

Source:

November 27, 2005
geometry3D geometryfrustumrationumber theoryrelatively prime

Problem Statement

A solid in the shape of a right circular cone is 4 inches tall and its base has a 3-inch radius. The entire surface of the cone, including its base, is painted. A plane parallel to the base of the cone divides the cone into two solids, a smaller cone-shaped solid CC and a frustum-shaped solid FF, in such a way that the ratio between the areas of the painted surfaces of CC and FF and the ratio between the volumes of CC and FF are both equal to kk. Given that k=m/nk=m/n, where mm and nn are relatively prime positive integers, find m+nm+n.