Question

One room of an apartment is 12 ft. by 15 ft. The walls are 9 1/2 feet high. How much paint will you need to paint the four walls if one gallon is enough to cover 425 square feet (round to nearest tenth)?
(A) 1.8 gallons
(B) 2.1 gallons
(C) 1.5 gallons
(D) 1.7 gallons
(E) 1.2 gallons

Answer 1

-- The left side wall and the right side wall are each (15 x 9) = 135 square ft.

-- The front wall and the back wall are each (12 x 9) = 108 square ft.

-- The total area of all 4 walls is (135 + 108 + 135 + 108) = 486 square ft.

-- You need 1 gallon of paint for every 425 square ft.
How many times will you need to cover 425 square ft ?

         486 / 425 = 1.144 times

-- So you need  1.144 gallons in order to paint all 4 walls.
When rounded to the nearest 1/10th gallon, the number is 1.1 gallons.
That choice is not found on the list of choices given with the question.

-- Even so, that figure of "1.1 gallons" is probably a little more than you
actually need in order to paint the 4 walls . . .  That quantity of paint includes
enough to paint over the door, the windows, and all of the electrical outlets !