Question

Peter wants to put 2 coats of paint on both the inside and outside of the walls. There are 5 walls, each side having 45 ft2 of paintable surface. A gallon of paint covers x ft2. Explain how to write an expression to represent the number of gallons of paint Peter needs.

Answer 1

Both sides of one wall would be 90 square feet. Two coats of paint for both sides would be 180 square feet. There are 5 walls, so the total square feet to be painted is 5(180) = 900. So, Peter needs 900/x gallons of paint.