# Problem #1645

 1645 Roy bought a new battery-gasoline hybrid car. On a trip the car ran exclusively on its battery for the first 40 miles, then ran exclusively on gasoline for the rest of the trip, using gasoline at a rate of 0.02 gallons per mile. On the whole trip he averaged 55 miles per gallon. How long was the trip in miles? $\text{(A)}\,140 \qquad\text{(B)}\,240 \qquad\text{(C)}\,440 \qquad\text{(D)}\,640 \qquad\text{(E)}\,840$ This problem is copyrighted by the American Mathematics Competitions.
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• Reduce fractions to lowest terms and enter in the form 7/9.
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