A car travels 70 miles in 9 hours. What is its average speed?
The average speed is 7.7777778 mph.
How to work it out
- 1
Write down what you know: distance d = 70 miles, time t = 9 hours. You are asked for the speed v.
- 2
Use the formula speed = distance ÷ time:
- 3
Answer with the unit: 7.7777778 mph.
- 4
The same formula rearranged: distance = speed × time (7.7777778 × 9 = 70 miles) and time = distance ÷ speed (70 ÷ 7.7777778 = 9 hours).
LaTeX source of the formulas on this page
\[ v = \frac{d}{t} = \frac{70}{9} = 7.7777778\ \text{mph} \]
\[ v = \frac{d}{t} = \frac{70}{9} = \frac{70}{9} = 7.7777778 \]How far at 7.7777778 mph
| Time | Distance |
|---|---|
| 0.5 hours | 3.8888889 miles |
| 1 hour | 7.7777778 miles |
| 2 hours | 15.555556 miles |
| 3 hours | 23.333333 miles |
| 4 hours | 31.111111 miles |
| 5 hours | 38.888889 miles |
Questions
What is the speed if a car travels 70 miles in 9 hours?
The average speed is 7.7777778 mph.
How far does it go in 3 hours at that speed?
23.333333 miles.