how long was each sprinkler used?
The Bennett family and the Hill family each used their sprinklers last summer. The water output rate for the Bennett family's sprinkler was 25L per hour. The water output rate for the Hill family's sprinkler was 15L per hour. The families used their sprinklers for a combined total of 55 hours, resulting in a total water output of 1075L. How long was each sprinkler used?