Another application of unit conversions is to calculate fuel economy. Fuel economy of vehicles compares the distance the vehicle can go compared to the amount of fuel it uses or the cost of the fuel. In this next video, we use unit conversion to determine the cost of a delivery. The following video will explain how to solve this example:

Unit Conversions for Fuel Economy

Video Source (08:53 mins) | Transcript

Even though our conversion factors look different, the process is the same. Before starting the problem, scan the question to find the conversion rates it gives you, then complete the steps below:

- Start with what you know.
- Determine what you want to get in the end. (Figure out what the end units should be.)
- Determine what conversion factor(s) to use. You may sometimes need more than one.
- Multiply by 1 in the form of the conversion factor that cancels out the unwanted units.

## Additional Resources

- Khan Academy: Multiple Units Word Problem: Road Trip (03:46 mins; Transcript)

### Practice Problems

1. You are planning to go on a trip with some friends. Your vehicle gets 25 miles per gallon (mpg), and you want to drive from Los Angeles to San Francisco. San Francisco is 382 miles away. The current gas price is $3.75 per gallon. How much will the gas for your trip cost, in US Dollars? Round to the nearest penny (hundredth).25 mi = 1 gal

$3.75 = 1 gal

(

Solution

10 gal = 120 mi

$3.55 = 1 gal

(

Solution

$9 = 1 gal

3 oz = 1 night

1 gal = 128 oz

(

Solution

1 L = 1000 ml

1 km = 1000 m

(

Solution

5 L = 100 km

€1.50 = 1 L

(

Solution

## Need More Help?

- Study other Math Lessons in the Resource Center.
- Visit the Online Tutoring Resources in the Resource Center.
- Contact your Instructor.
- If you still need help, Schedule a Tutor.