Question

The Nguyen family and the Reed family each used their sprinklers last summer. The Nguyen family's sprinkler was used for 15 hours. The Reed family's sprinkler was used for 25 hours. There was a combined total output of 1175L of water. What was the water output rate for each sprinkler if the sum of the two rates was 55L per hour? Nguyenfamily'ssprinkler:Lperhour Reedfamily'ssprinkler:Lperhour

Answer 1

• Nguyen family's sprinkler: 20 L per hour
• Reed family's sprinkler: 35 L per hour

Explanation:

Let n and r represent the output in liters per hour of the Nguyen and Reed family sprinklers, respectively. Then we have ...

15n +25r = 1175 . . . . total sprinkler output

n + r = 55 . . . . . . . . . sum of two output rates

The second equation tells us we can substitute n = 55 -r into the first equation:

15(55 -r) +25r = 1175

10r = 1175 -825 . . . . . . subtract 825

r = 350/10 = 35 . . . . . . divide by 10

n - 55 -35 = 20 . . . . . . find n from r

Nguyen family's sprinkler: 20 L per hour

Reed family's sprinkler: 35 L per hour