Question

The Russell family and the Gonzalez family each used their sprinklers last summer. The water output rate for the Russell family's sprinkler was 35L per hour. The water output rate for the Gonzalez family's sprinkler was 40L per hour. The families used their sprinklers for a combined total of 60 hours, resulting in a total water output of 2200L. How long was each sprinkler used?

Answer 1

Answer:

Russell family's sprinkler: 40 hours

Gonzales family's sprinkler: 20 hours

Step-by-step explanation:

Let's call the amount of time the Russell family's sprinkler was on by X, and the Gonzales family's sprinkler by Y.

We can then formulate the equations:

X + Y = 60

X*35 + Y*40 = 2200

We can solve this system multiplying the first equation by 35, and then subtracting the result from the second equation:

35*X + 35*Y = 2100

5*Y = 100

Y = 20

from the first equation:

X + 20 = 60

X = 40

Russell family's sprinkler: 40 hours

Gonzales family's sprinkler: 20 hours