Calculate the miles per gallon expected for a car which weighs 2800 lb, has a drag coefficient of 0.44, a frontal area of 34 square feet, and is traveling at a stead speed of 65 mph up a 15% slope with no wind. Assume the delivery energy is 20% of the fuel energy of gasoline. The heat of combustion/energy content of gasoline is 124,000 Btu/gallon..