If the walls in a room are 955 square feet in area and a gal

If the walls in a room are 955 square feet in area, and a gallon of paint covers 15 square yards, how many gallons of paint are needed for the room? (3 ft = 1 yd)

A) 2.3 gallons

B) 24 gallons

C) 7.1 gallons

D) 47 gallons

E) 21 gallons

I know the answer is C, but can someone please explain to me how? I keep getting 21 gallons

Solution

We know that 1 square yard = 3*3 = 9 square feet. Hence 15 square yards = 15*9 = 135 square feet. Further, since 15 square yards or, 135 square feet area is covered by 1 gallon of paint, therefore 955 square ft. area will becovered by (1/135)*955 = 7.07gallons of paint or 7.1 gallons of paint ( on roundingoff to 1 decimal place). The answer is C