1. The height of the frustum of a cone is 3 m, the diameter of one base is twice that of the other. The slant height of the frustum is inclined to the greater base at an angle of 450. Find the volume of the frustum.
2. A block of wood is in the form of a right circular cone. The altitude is 12 cm and the radius of the base is 5 cm. A cylindrical hole of 5 cm is bored completely through the solid, the axis of the hole coinciding with the axis of the cone. Find the amount of wood left after the hole is bored.
3. Find the radius of a cone of revolution of slant height 6 inches in which the total area is twice the lateral area.
4. In a frustum of right circular cone the altitude is 3 cm and the radii of the bases are 2 cm and 6 cm. Find the lengths of the slant height and altitude of the entire cone of which this frustum is a part.