SOLUTION: The Edwards family and the Chen family each used their sprinklers last summer. The water output rate for the Edwards family's sprinkler was 30L per hour. The water output rate for

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Question 872783: The Edwards family and the Chen family each used their sprinklers last summer. The water output rate for the Edwards family's sprinkler was 30L per hour. The water output rate for the Chen family's sprinkler was 20L per hour. The families used their sprinklers for a combined total of 65 hours, resulting in a total water output of 1700L . How long was each sprinkler used?
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Volume per Hour uniform rates problem.
RT=V for rate, time, volume.


__________________rate__________time__________volume
Edwards___________30____________x_____________30x
Chen______________20____________y_____________20y
Totals__________________________65____________1700

Implied variables x and y.
Two obvious equations are the time sum x%2By=65 and volume sum 30x%2B20y=1700.

Volume equation simplifies to 3x%2B2y=170 and the time sum equation is equivalent to 2x%2B2y=130, allowing for partial use of Elimination Method.
1%2Ax=40, a fast answer result: highlight%28x=40%29 hours. highlight%28y=25%29 hours for Chen family.