Please solve word problem below?

Question

The Martinez family and the Richardson family each used their sprinklers last summer. The water output rate for the Martinez family’s sprinkler was 35 L per hour. The water output rate for the Richardson family’s sprinkler was 15 L per hour. The families used their sprinklers for a combined total of 55 hours l, resulting in a total water output of 1225 L. How long was each sprinkler used?

Answer 1

Assume that Martize used 35L/hour and Richardson 15L/hour.

Let's assume that x is the hours that Martinez used and y is the hours that Richardson used.

We know for a fact that the total of their hours is equal to 55, so

x+y=55

We also know that

35x= total liters that Martinez used

15y=total liters that Richardson used

35x+15y=1225

From here we can use both of the equations, x+y=55 and 35x+15y=1225 to solve for x and y. (use simultaneous equation method).

First, multiply x+y=55 by 35, so that we can eliminate x to get y.

35x+15y=1225

35x+35y=1925

Then, subtract the bottom equation from the top. That completely eliminates 35x and subtract 35y from 15y and subtract 1925 from 1225. This will result

-20y=-700

y=35

After this, just plug in y to solve for x.

x+35=55

x=20

Martized used 20 hours while Richardson used 35 hours.