A mathematician, a physicist, and an engineer were each handed a red rubber ball and asked to determine the volume. Each ball had a diameter of 2 inches. The mathematician plugged the radius of 1 inch into the equation for the volume of a sphere. The physicist put a known volume of water into a calibrated container, submerged the ball, and with a simple subtraction determined the volume. The engineer said he couldn't answer the question. His handbooks had a blue rubber ball table and a green rubber ball table, but no red rubber ball table.