A car travels 210 miles in 10 hours. What is its average speed?
The average speed is 21 mph.
How to work it out
- 1
Write down what you know: distance d = 210 miles, time t = 10 hours. You are asked for the speed v.
- 2
Use the formula speed = distance ÷ time:
- 3
Answer with the unit: 21 mph.
- 4
The same formula rearranged: distance = speed × time (21 × 10 = 210 miles) and time = distance ÷ speed (210 ÷ 21 = 10 hours).
LaTeX source of the formulas on this page
\[ v = \frac{d}{t} = \frac{210}{10} = 21\ \text{mph} \]
\[ v = \frac{d}{t} = \frac{210}{10} = 21 \]How far at 21 mph
| Time | Distance |
|---|---|
| 0.5 hours | 10.5 miles |
| 1 hour | 21 miles |
| 2 hours | 42 miles |
| 3 hours | 63 miles |
| 4 hours | 84 miles |
| 5 hours | 105 miles |
Questions
What is the speed if a car travels 210 miles in 10 hours?
The average speed is 21 mph.
How far does it go in 3 hours at that speed?
63 miles.