1. Sand is pouring into a conical pile at the rate of 15 cubic feet per minute. The verticle cross-section is an isosceles right triangle. How fast is the height of the pile increasing when the height is 5 feet? 2. At a certain moment the radius of the base of a right circular cone is 8 inches and is increasing at the rate of 5 inches per second, while the height of the cone is 7 inches and is decreasing at the rate of 4 inches per second. Is the volume of the cone increasing or decreasing at that moment and at what rate?