Average...?

In a family there are two cars. The sum of the average miles per gallon obtained by the two cars in a particular week is . The first car has consumed gallons during that week, and the second has consumed gallons, for a total of miles driven by the two cars combined. What was the average gas mileage obtained by each of the two cars in that week?|||Let's put some names on the spaces you left lol :


Sum of gas mileage is : gs


First car's consumption in gallons is : c1


Second car's consumption in gallons is : c2


Total of miles : mt


Gas mileage of first car : g1


Gas mileage of second car : g2


I'm even adding some :


m1 : miles for first car


m2 : miles for second car





Let's write some equations to translate your hypothesis :


g1 + g2 = gs


t = m1 + m2


But we can express the miles as :


m1 = g1 * c1, and m2 = g2 * c2





So, given ga, t, c1 and c2, we want g1 and g2, given :


g1 + g2 = gs


g1*c1 + g2*c2 = t


This is solved by taking : g2 = gs-g1, so in the second equation :


g1*c1 + (gs-g1)*c2 = t


g1 * ( c1 - c2 ) = t - c2*gs





So : g1 = (t - c2*gs) / (c1-c2)


and : g2 = (t - c1*gs) / (c1-c2)


This is your answer.





Oh, now you added the numbers :


gs = 55, c1 = 30, c2 = 15, t = 1425.


In that case :


g1 = 15, g2 = 40|||first car: 10. 55555555....


second car: 21.111...





sorry if im wrong...





edit: oops i made a mistake. Give someone else 10 pts|||A lot of damn gas money|||To find gas mileage, divide the number of miles driven by the amount of gas used in gallons.|||It was average.