Question

The Sanchez family and the Bryant family each used their sprinklers last summer. The water output rate for the Sanchez family's sprinkler was 40L per hour. The water output rate for the Bryant family's sprinkler was 20L per hour. The families used their sprinklers for a combined total of 60 hours, resulting in a total water output of 1900L . How long was each sprinkler used?

Answer 1

Sanchez family used sprinkler for 35 hours.

Bryant family used it for 25 hours.

Explanation:

Water output rate for Sanchez family's sprinkler = 40 liters/hour

Water output rate for Bryant family's sprinkler = 20 liters/hour

Assuming x to be the number of hours sprinkler was used by Sanchez family; and

y to be the number of hours sprinkler was used by Bryant family, we can write it as:

x + y = 60 --- (equation 1)

40x + 20y = 1900 --- (equation 2)

Solve for x from equation 1:

x + y = 60

x = 60 - y ---> put this value in equation 2

40x + 20y = 1900

40 (60 - y) + 20y = 1900

2400 - 40y + 20y = 1900

-20y = -500

y = 25

x = 60 -y

x = 60 - 25

x = 35

Therefore, Sanchez family used sprinkler for 35 hours while Bryant family used it for 25 hours.