Answer:
30 miles
Explanation:
In this context, "per" means "divided by", so to find miles per gallon, divide miles by gallons:
(56 1/4 mi)/(1 7/8 gal) = 30 mi/gal
The vehicle can travel 30 miles per gallon of gas.
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My calculator divides mixed numbers directly, as many graphing calculators do. If you're working this out by hand, you can convert to improper fractions, then multiply the numerator by the inverse of the denominator.
(56 1/4)/(1 7/8) = (225/4)/(15/8)
= (225/4)·(8/15) = (225/15)·(8/4)
= 15·2 = 30