A car travels 400 miles in 5 hours. What is its average speed?
The average speed is 80 mph.
How to work it out
- 1
Write down what you know: distance d = 400 miles, time t = 5 hours. You are asked for the speed v.
- 2
Use the formula speed = distance ÷ time:
- 3
Answer with the unit: 80 mph.
- 4
The same formula rearranged: distance = speed × time (80 × 5 = 400 miles) and time = distance ÷ speed (400 ÷ 80 = 5 hours).
LaTeX source of the formulas on this page
\[ v = \frac{d}{t} = \frac{400}{5} = 80\ \text{mph} \]
\[ v = \frac{d}{t} = \frac{400}{5} = 80 \]How far at 80 mph
| Time | Distance |
|---|---|
| 0.5 hours | 40 miles |
| 1 hour | 80 miles |
| 2 hours | 160 miles |
| 3 hours | 240 miles |
| 4 hours | 320 miles |
| 5 hours | 400 miles |
Questions
What is the speed if a car travels 400 miles in 5 hours?
The average speed is 80 mph.
How far does it go in 3 hours at that speed?
240 miles.