Units conversion

Question

A certain hybrid car has a mileage rating of 55 miles per gallon. If the car makes a trip of 271 miles, how many gallons of gasoline will be used?

Answer 1

This is a good example of dimensional analysis. In order to solve this questions, you want to make sure the units that your answer is will be in the numerator. In this case, the answer is in gallons, so we know that gallons will be in the numerator.

First, start with your setup: 271 miles x (1 gallon/55 miles) = 271 miles x 1 gallon / 55 miles

The miles units will cancel out, and you will get: 271 gallons / 55 = 4.93 gallons.

And that's your answer! (4.93 gallons)