Question

A family has two cars. During one particular week, the first car consumed 40 gallons of gas and the second consumed 35 gallons of gas. The two cars drove a combined total of 2125 miles, and the sum of their fuel efficiencies was 55 miles per gallon. What were the fuel efficiencies of each of the cars that week?

Answer 1

Answer:

Car 1 : 40 gallons

Car 2 : 15 gallons

Step-by-step explanation:

F = Car 1 Fuel Efficiency

S = Car 2 Fuel Efficiency

F + S = 55

40F + 35S = 2125

Using the first equation...

S = 55 - F

Then substitute into the second equation.

40F + 35(55 - F) = 2125

Simplify

40F + 1925 - 35F = 2125

5F + 1925 = 2125

5F = 200

F = 40

Then plug it back into S = 55 - F

S = 15

Plug it back into F + S = 55 to check.

Hope this helps.