A car travels 140 miles in 7 hours. What is its average speed?
The average speed is 20 mph.
How to work it out
- 1
Write down what you know: distance d = 140 miles, time t = 7 hours. You are asked for the speed v.
- 2
Use the formula speed = distance ÷ time:
- 3
Answer with the unit: 20 mph.
- 4
The same formula rearranged: distance = speed × time (20 × 7 = 140 miles) and time = distance ÷ speed (140 ÷ 20 = 7 hours).
LaTeX source of the formulas on this page
\[ v = \frac{d}{t} = \frac{140}{7} = 20\ \text{mph} \]
\[ v = \frac{d}{t} = \frac{140}{7} = 20 \]How far at 20 mph
| Time | Distance |
|---|---|
| 0.5 hours | 10 miles |
| 1 hour | 20 miles |
| 2 hours | 40 miles |
| 3 hours | 60 miles |
| 4 hours | 80 miles |
| 5 hours | 100 miles |
Questions
What is the speed if a car travels 140 miles in 7 hours?
The average speed is 20 mph.
How far does it go in 3 hours at that speed?
60 miles.