Question

the amount of water a washing machine uses varies directly with the number of loads of laundry washed. if a machine uses 65 gallons of water to wash 5 loads, how much water will be used to was 8 loads?

Answer 1

Let g represent gallons of water and let L represent loads.

Here, the gallons of water varies directly with the number of loads, thus we have:

g ∝ L

Now introduce a constant k:

g = kL

65 gallons is used to wash 5 loads, thus we have:

65 = k * 5

Let's solve for k:

65 = 5k

Divide both sides by 5:

$\begin{gathered} \frac{65}{5}=\frac{5k}{5} \\ \\ 13=k \end{gathered}$

To find the amount of water that will be used to wash 8 loads, we have:

g = kl

We are to find g, substitute 13 for k and 8 for l:

g = 13 x 8

g = 104

Therefore, to wash 8 loads, 104 gallons of water is needed.

ANSWER:

104