Question

The Price family and the Jenkins family each used their sprinklers last summer. The water output rate for the Price family's sprinkler was 20L per hour. The water output rate for the Jenkins family's sprinkler was 35L per hour. The families used their sprinklers for a combined total of 45 hours, resulting in a total water output of 1200L. How long was each sprinkler used? URGENT!!!!

Answer 1

Set up two equations:

1st:  P (for Price family) + J (for Jenkins family) = 45 hours

2nd: 20P + 35J = 1200 liters

Rewrite the first equation as P = 45 – J

Replace P in the second equation:

20(45-J) + 35J = 1200

Simplify:

900 -20J + 35J = 1200

900 +15J = 1200

Subtract 900 from both sides:

15J = 300

Divide both sides by 15:

J = 300/15

J = 20

Jenkins used theirs for 20 hours

Price used theirs for 45-20 = 25 hours.