A car travels 310 miles in 11 hours. What is its average speed?

The average speed is 28.181818 mph.

v = \frac{d}{t} = \frac{310}{11} = 28.181818\ \text{mph}

How to work it out

1
Write down what you know: distance d = 310 miles, time t = 11 hours. You are asked for the speed v.
2
Use the formula speed = distance ÷ time:
$v = \frac{d}{t} = \frac{310}{11} = \frac{310}{11} = 28.181818$
3
Answer with the unit: 28.181818 mph.
4
The same formula rearranged: distance = speed × time (28.181818 × 11 = 310 miles) and time = distance ÷ speed (310 ÷ 28.181818 = 11 hours).

LaTeX source of the formulas on this page

\[ v = \frac{d}{t} = \frac{310}{11} = 28.181818\ \text{mph} \]
\[ v = \frac{d}{t} = \frac{310}{11} = \frac{310}{11} = 28.181818 \]

What is the speed if a car travels 310 miles in 11 hours?

The average speed is 28.181818 mph.

How far does it go in 3 hours at that speed?

84.545455 miles.