Aaron is painting all 4 walls of his room. each wall is 8 feet by 12 feet. one wall has a 4 foot by 5 foot window and one wall has a 3 foot by 7.5 foot door. neither of these will be painted. aaron only wants to paint one coat on each wall. he learns that each gallon of paint will cover 125 ft^2. he can only buy entire gallons of paint. how many gallons of paint will he need?