If 3/4 of a gallon of paint covers 2/5 of a wall, then how many gallons are needed to paint the entire wall?

1 Answer
Feb 16, 2017

2 gallons of paint

Explanation:

If 3/4 of a gallon covers 2/5 of a wall, this means that a half of 3/4 gallons can cover 1/5 of a wall.

By knowing this, you can just make up your own expression
(the trick is to find a way to break it down to one, so you can multiply and manipulate it to save yourself some brain cells)

# 1/5 + 1/5 + 1/5 + 1/5 + 1/5# = whole wall

if #(3/4)/2 = 3/8# = amount of paint to cover 1/5 wall

then #(3/8)*5 = 3/8 + 3/8 + 3/8 + 3/8 + 3/8 = 15/8 ~~ 1.875#

since we're talking about real life it would be 2 gallons of paint instead of 1.875 gallons to paint the whole wall