we have
Walker family= 20 L/H
James family = 35 L/H
Total time= 50h
total water= 1300L
let's x be the time walker family use the sprinkler
let's y be the time James family use the sprinkler
then the total time is given by
First equation
![x+y=50](https://img.qammunity.org/2023/formulas/mathematics/college/994vo89rfgudqr6u3w1acz4ze04fta30f6.png)
second equation
then the flow of water of is
Walker family = x*20
James Family = y*35
since the total flow is 1300L
then
![(x\ast20)+(y\ast35)=1300](https://img.qammunity.org/2023/formulas/mathematics/high-school/ly70ppj3r6b0j483zvw4gnfn0e99dlnz73.png)
![20x+35y=1300](https://img.qammunity.org/2023/formulas/mathematics/high-school/lpz956kpm2rne2a49mwo67xx6bfcw7p1ul.png)
now with the 2 system equation we can solve x and y
![x=50-y](https://img.qammunity.org/2023/formulas/mathematics/high-school/80u0dpaldppc4xzx9ts4l4rey7tq8r4ill.png)
then
![20(50-y)+35y=1300](https://img.qammunity.org/2023/formulas/mathematics/high-school/7ny0wkre1yxv132teid86cjvi97tdfje0v.png)
![1000-20y+35y=1300](https://img.qammunity.org/2023/formulas/mathematics/high-school/7fej7m0mu13j5pntcmmvjzc4ocltt6tkze.png)
![15y=300](https://img.qammunity.org/2023/formulas/mathematics/high-school/31k5jsdzp0mwwjowzt3xpabzkmeman7hph.png)
![y=(300)/(15)=20](https://img.qammunity.org/2023/formulas/mathematics/high-school/ph6lm1gnw55fgjfszy7k4z19j1p9n1db45.png)
then
x+20=50
x=50-20=30
wich means
the walker family use the sprinkler for 30h
and
the James family use the sprinkler for 20h