Suppose you are a conservation-minded consumer who cannot afford to purchase a new car. You have the option to rent one of two cars: a 10-year old Buick or a 10-year old Toyota. The Buick will cost $100/year and gets 20 miles-per-gallon, while the Toyota cost $500/year and gets 40 miles-per-gallon. Assuming the price of a gallon of gas is $2, should you rent the Buick or the Toyota? Explain.