Mixture problemz

Question

Two family's each have sprinkler systems.

Family A used 15 hours of use

Family B used 40 hours use

Combined total water output is 1400L of water.

If the sum of the Two rates was 60L per hour. What was the water output rate for each family?

Answer 1

15*r1 + 40*r2 = 1400

r1 + r2 = 60 ---> r2 = 60 - r1

15*r1 + 40( 60 - r1) = 1400

15*R1 + 2400 - 40*R1 = 1400

-25*r1 = -1000

R1 = 40

R2 = 20