VJesus12 wrote:A certain car averages 25 miles per gallon when driving in the city and 40 miles per gallon when driving on the highway. According to these rates, which of the following is closest to the number of miles per gallon that the car averages when it is driven 10 miles in the city and then 50 miles on the highway?

A. 28
B. 30
C. 33
D. 36
E. 38

[spoiler]OA=D[/spoiler]

Source: GMAT Prep

Time taken to drive 10 miles in city = 10/25 = 2/5 hours;
Time taken to drive 50 miles in city = 50/40 = 5/4 hours

Total time taken = 2/5 + 5/4 = 33/20 hours

Total distance = 10 + 50 = 60 miles

Average speed = Total distance / Total time = 60 / (33/20) = appx 36 miles per hour

The correct answer: D

Hope this helps!

-Jay
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