A homeowner called in a painter to paint the walls and ceiling of one bedroom. His bedroom is 18ft. long, 12 ft. wide, and 8 ft. high. The room has two doors, each 3 ft. by 7ft. and three windows each 3ft. by5 ft. The doors and windows do not have to be painted. A gallon of paint can cover 300ft2. A hired painter claims he will need 4 gallons. Show that his estimate is too high.