SOLUTION: The Stewart family and the James family each used their sprinklers last summer. The water output rate for the Stewart family's sprinkler was 35L per hour. The water output rate for
Question 1111987: The Stewart family and the James family each used their sprinklers last summer. The water output rate for the Stewart family's sprinkler was 35L per hour. The water output rate for the James family's sprinkler was 30L per hour. The families used their sprinklers for a combined total of 45 hours, resulting in a total water output of 1500L. How long was each sprinkler used?
Stewart familys sprinkler:____hours
James familys sprinkler:____hours Found 2 solutions by josgarithmetic, greenestamps:Answer by josgarithmetic(39618) (Show Source): You can put this solution on YOUR website!
FAMILY RATE TIME VOLUME
Stewart 35 t 35t
James 30 45-t 30(45-t)
Total 45 1500
If you don't need to use formal algebra to solve the problem, here is an easy way to get the answer to this kind of problem with a little mental arithmetic.
If all 45 hours of water used had been by the James family, the total water usage would have been 45*30 = 1350L -- 150L short of the actual total.
The Stewart family's sprinkler uses 5L more per hour than the James family's; to get those "extra" 150L of water usage, the number of hours the Stewart family's sprinkler had to be running is 150/5 = 30.
And that leaves 45-30 = 15 hours for the James family's sprinkler.