Answer:
The Torres family's output rate is 20 L per hour and
the Ross family's output rate is 15 L per hour
Step-by-step explanation:
The Torres family and the Ross family each used their sprinklers last summer.
Let x = the Torres family's sprinkler output rate.
Let y = the Ross family's sprinkler output rate.
The Torres family's sprinkler was used for 30 hours. The Ross family's sprinkler was used for 20 hours. This means that both family's sprinklers were used for ( 30x + 20y ) hours.
There was a combined total output of 850 L of water. Therefore,
30x + 20y = 850 - - - - - - - - - 1
The sum of the two rates was 35 L per hour. This means
x + y = 35
x = 35 - y
Put x = 35-y in equation 1. It becomes
30(35-y) + 20y = 850
1050 - 30y + 20y = 850
-30y + 20y = 850 - 1050
-10y = -200
y = 200/10 = 20 L per hour
Put y = 20 in y = 35-x
y = 35 - 20 = 15
