math
posted by heatherly on .
A room measures 15 ft by 19 ft. The ceiling is 10 ft above the floor. The door is 3 ft by 7 ft. A gallon
of paint will cover 78.2 ft2. How many gallons of paint are needed to paint the room (including the
ceiling and not including the door). Round your answer up to the next whole number.

Two walls are 15' x 10' = 150+150 ft^2.
Two walls are 19' x 10' = 190+190 ft^2
The door subtracts 3' x 7' = 21 ft^2
Add (and subtract) to obtain the final area, then divide by 78.2 to obtain gallons needed. check my work. 
What about the ceiling, Should you add another 15x19 area then divide by 78.2 to get the amount of gallons needed?

so approx. 9 gal.