A rate is a ratio that compares two related quantities. Common rates are speed = \({distance \over time}\), flow = \({amount \over time}\), and defect = \({errors \over units}\).
How many hours does it take a car to travel 15 miles at an average speed of 15 miles per hour?
| 7 hours | |
| 9 hours | |
| 5 hours | |
| 1 hour |