Question

You are going to mix a gallon bucket of window cleaner. The instructions direct you to mix 1 part cleaner to 3 parts water. How much cleaning solution will you need to use?
A) 1 ½ quarts B)1 pint C) 2 quarts D) 1 quart

Answer 1

One gallon equals to 4 quarts.

The instructions tell you to add 1 part of cleaner and 3 parts of water, in total 4 parts. It makes it easy as you can take that one part = one quart.

You will use 3 quarts of water and 1 quart of cleaner. The answer is D.

Answer 2

Let
x--------> gallons of cleaner
y-------> gallons of water

we know that
$x+y=1$ equation 1
and
$\frac{x}{y} = \frac{1}{3} \\ y=3x$ equation 2
substitute equation 2 in equation 1
$x+3x=1 \\ 4x=1 \\ x=1/4 gal$

find the value of y
$y=3x \\ y=3* \frac{1}{4} \\ y= \frac{3}{4} gal$

we know that
$\frac{1}{4} gal$ is equal to $1 quart$

therefore
the answer is the option
D) 1 quart