A family has two cars. The first car has a fuel efficiency of 15 miles per gallon of gas and the second has a fuel efficiency of 30 miles per gallon of gas. During one particular week, the two cars went a combined total of 825 miles, for a total gas consumption of 40 gallons. How many gallons were consumed by each of the two cars that week?

Question

A family has two cars. The first car has a fuel efficiency of  15  miles per gallon of gas and the second has a fuel efficiency of  30  miles per gallon of gas. During one particular week, the two cars went a combined total of  825  miles, for a total gas consumption of  40  gallons. How many gallons were consumed by each of the two cars that week?

xapproachesinfinity · Answer

15x+30y=825
x+y=40
let x be the gallons consumed by the first car
and y the gallons ...................by the 2nd car
by solving this system you will get the gallons that each one consumed