Average

[Nidhs]

A certain car averages 25 miles per gallon of gasoline when driven in the city and 40 miles per gallon when driven on the highway. According to these rates the following is the closest to the number of miles per gallon that the car averages when it is driven at 10 miles in the city and then 50 miles on the highway?
1)28
2)30
3)33
4)36
5)38

Ans is D. Can somebody please explain.

[ikant]

Hello,

To calculate the average miles per gallon = Total miles / Total gallons spent.

Total miles = 60 miles

Gallons spent in city = 10 / 25

Gallons spent in highway = 50 / 40

Therefore avg gallon miles per gallon = 60 / [ (10/25) + (50/40) ]

= 36.3

so answer id D.