Question

The Morris family and the Tran family each used their sprinklers last summer. The water output rate for the Morris family's sprinkler was 40 L per hour. The water output rate for the Tran family's sprinkler was per hour30 L. The families used their sprinklers for a combined total of 50 hours, resulting in a total water output of 1900 L.
How long was each sprinkler used?

Answer 1

Answer:the number hours that the Morris family used their sprinklers last summer is 40

the number hours that the Tran family used their sprinklers last summer is 10

Step-by-step explanation:

Let x represent the number hours that the Morris family used their sprinklers last summer.

Let y represent the number hours that the Tran family used their sprinklers last summer.

The families used their sprinklers for a combined total of 50 hours. This means that

x + y = 50

The water output rate for the Morris family's sprinkler was 40 L per hour. The water output rate for the Tran family's sprinkler was 30L per hour. The total water output was 900L. This means that

40x + 30y = 900 - - - - - - - - - - 1

Substituting x = 50 - y into equation 1, it becomes

40(50 - y) + 30y = 1900

2000 - 40y + 30y = 1900

- 40y + 30y = 1900 - 2000

- 10y = - 100

y = - 100/- 10 = 10

Substituting y = 10 into x = 50 - y, it becomes

x = 50 - 10 = 40