Average miles per gallon is given by: Total distance traveled/Total gallons used.

Total distance traveled is given to us and is equal to 10+50 = 60 miles

Total gallons used can be determined by reverse working the formula listed above.

Number of gallons in the city = Total distance / Average = \(\frac{10}{25}\)

Number of gallons in the highway = Total distance / Average = \(\frac{50}{40}\)

Total number of gallons = Sum of the above two quantities.

So the average overall

\(\frac{60}{\frac{10}{25} + \frac{5}{4}} = \frac{60}{\frac{2}{5} + \frac{5}{4}} =
\frac{60}{\frac{33}{20}} = \frac{1200}{33} = \frac{400}{11}\)

If you solve this you get 36.3636. So the answer is 36.

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https://gre.myprepclub.com/forum/how-to-so ... tml#p53778

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