Question

A family has two cars. The first car has a fuel efficiency of 35 miles per gallon of gas and the second has a fuel efficiency of 20 miles per gallon of gas. During one particular week, the two cars went a combined total of 2025 miles, for a total gas consumption of 75 gallons. How many gallons were consumed by each of the two cars that week?

Answer 1

Hello,

Let's assume a the number of miles done by the 1 vehicule (35 mi/gal)
2025-a is the number of miles done by the 2nd vehicule (20 mi/gal)


`(a)/(35) + (2025-a)/(20) =75\\\\ 4a+(2025-a)*7=10500\\\\ -3a=10500-7*2025\\\\ 3a=-3675\\\\ a=1225(miles)\\\\`

The gas consumption of the 1 vehicule is 1225/35=35 (gallons)
The gas consumption of the 2 vehicule is 75-35=40 (gallons)