In: Advanced Math
Ti Fan and his wife have retired. They are touring the USA in a big recreational vehicle (RV). They are towing a Prius car, which they use for running errands when the RV is parked. However, towing the Prius decreases the gas mileage of the RV by 25%. Ti Fan wonders if they would save gas if his wife drives the Prius instead of towing it. The Prius gets good mileage, 50 miles per gallon. Ti Fan has never wanted to know the mileage of the RV, since it would be discouraging. Nonetheless, he looks at the odometer when he fills the RV's gas tank, then looks again when he fills it again. Towing the Prius, he drove 255 miles and burned 37 gallons of gas. How much would they save, in gallons, if they had travelled the 255 miles with his wife driving the Prius while Ti Fan drove the RV?