A rate is a ratio that compares two related quantities. Common rates are speed = \({distance \over time}\), flow = \({amount \over time}\), and defect = \({errors \over units}\).
If a car travels 225 miles in 5 hours, what is the average speed?
| 45 mph | |
| 15 mph | |
| 40 mph | |
| 20 mph |