a Hummer that gets 300 miles on 20 gallons of gas or a Camry that gets 495 miles on 15 gallons of gas
Divide 300 by 20 and 495 by 15. Your answer for Hummer will be 15 miles on 1 gallon. Your answer for Camry is 33 miles on 1 gallon. So Camry is better.