The volume of a pyramid varies jointly with the base area of the pyramid and its height. the volume of one pyramid is 35 cubic inches when its base area is 15 square inches and its height is 7 inches. what is the volume of a pyramid with a base area of 36 square inches and a height of 5 inches?

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?