how many gallons of paints is needed if 1 can covers 400 square ft?

Question

a gallon can of paint covers 400 square feet. how many gallons are needed to paint two coats on the walls and ceiling of a rectangular room that is 30 ft long, 18 ft wide, and 8 ft high?

Answer 1

The surface area is 30x18 + 2*18x8 + 2*30x8 because the floor (30x18) does not get painted

 

  Total surface area for 1 coat of paint is 540 + 288 + 480 = 1308

 

 doubling that is 2616 square feet

 

2616/400 = 6.54 cans of paint