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?

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

answer: the first one

step-by-step explanation: use a calculator and divide the minutes by the dollars.