i think you would have to divide the money he had saved, which is $2,000 by the time he plans on exercising which is 40 hours, and the answer you get should tell you the answer to your question.
Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches. approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *