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Rate review

Review the basics of rates and try some practice problems.

What is a rate?

A rate is a ratio that compares two quantities with different units of measure.
Example of a rate:
A plane flew 765 kilometers in 3 hours.

Unit rates

A unit rate of two quantities in a ratio is the number of units of the first quantity for every 1 unit of the second quantity.
Examples of unit rates:
There are 60 minutes in 1 hour.
Jen types 42 words in 1 minute.
Want to learn more about rates? Check out this video.

Finding unit rates

To find a unit rate, we divide the first quantity in a rate by the second.
A plane flew 765 kilometers in 3 hours.
The plane flew at a rate of 255 kilometers per hour. We can also write the unit rate as 255 km:1 hour.
Want to learn more about solving unit rates? Check out this video.

Using unit rates to solve rate problems

Let's look at an example.
Mark can make 42 birthday cakes in 7 days.
How many birthday cakes can Mark make in 5 days?
First, we find the unit rate.
Mark makes cakes at a unit rate of 6 cakes for every 1 day.
Now, we can use the unit rate to find how many cakes Mark makes in 5 days.
In 5 days, Mark can make 30 cakes.


Problem 1
Frances can complete 91 oil changes in 7 days.
How many oil changes can Frances complete in 11 days?
  • Your answer should be
  • an integer, like 6
  • an exact decimal, like 0.75
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
oil changes

Want to try more problems like this? Check out this exercise.

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