Question

The Jenkins family and the Moore family each used their sprinklers last summer. The water output rate for the Jenkins family's sprinkler was 30 L per hour. Thewater output rate for the Moore family's sprinkler was 35 L per hour. The families used their sprinklers for a combined total of 60 hours, resulting in a totalwater output of 1925 L. How long was each sprinkler used

Answer 1

`\begin{gathered} x=\text{time Jenkins sprinkler} \\ y=\text{time Moores sprinkler} \\ x+y=60\text{ (1)} \\ 30x+35y=1925\text{ (2)} \\ \text{From (1)} \\ x=60-y \\ In\text{ (2)} \\ 30(60-y)+35y=1925 \\ 1800-30y+35y=1925 \\ 1800+5y=1925 \\ 5y=1925-1800 \\ 5y=125 \\ y=(125)/(5) \\ y=25 \\ \end{gathered}`