The Allen family and the Edwards family each used their sprinklers last summer. The water output rate for the Allen family's sprinkler was 20L per hour. The water output rate for the Edwards family's sprinkler was 35L per hour. The families used their sprinklers for a combined total of 60 hours, resulting in a total water output of 1575L. How long was each sprinkler used?

1 answer

Let x be the number of hours the Allen family used their sprinkler and y be the number of hours the Edwards family used their sprinkler.

From the problem, we can set up the following system of equations:

x + y = 60 (total hours used by both families)
20x + 35y = 1575 (total water output)

Multiplying the first equation by 20, we get:

20x + 20y = 1200

Subtracting this from the second equation, we get:

15y = 375
y = 25

Substituting y back into the first equation, we get:

x + 25 = 60
x = 35

So, the Allen family used their sprinkler for 35 hours and the Edwards family used their sprinkler for 25 hours.