Solution
[tex]\begin{gathered} Campell\text{ = x l/hour} \\ Bryanrt\text{ = 60-x l/hour} \end{gathered}[/tex][tex]\begin{gathered} 30(x)+20(60-x)=1550 \\ 30x+1200-20x=1550 \\ 10x=1550-1200 \\ 10x=350 \\ divide\text{ both sides by 10} \\ x=35 \\ \end{gathered}[/tex]Now
[tex]\begin{gathered} Campell=\text{ 35 L per hour} \\ \\ Bryant\text{ family=25 L per hour} \end{gathered}[/tex]