Answer:
x = 23.33 hr Rodriguez sprinkler
y = 26.66 hr Hill sprinkler
Step-by-step explanation: INCOMPLETE QUESTION
Requiered information:
the water output rate for both sprinkler families
We assume : Rodriguez family 40 lts/hr
Hill family 35 lts/ hr
Total water output 1900 lts
and total combined hours working is 50 hr
Let call "x" time in hours sprinkler of Rodriguez family worked
and "y" time in hours sprinkler of Hill family worked
Then if total output was 1900 lts
40*x + 35*y = 1900 and x + y = 50
We have a two equation system, solving
y = 50 - x ⇒ 40*x + 35 * ( 50 - x )
40x = 1750 - 35x
75 x = 1750 ⇒ x = 1750/75 ⇒ x = 23.33 hr
and y = 50 - 23.33 ⇒ y = 26.66 hr
