A car travels 20 km in 11 hours. What is its average speed?

The average speed is 1.8181818 km/h.

v = \frac{d}{t} = \frac{20}{11} = 1.8181818\ \text{km/h}

How to work it out

1
Write down what you know: distance d = 20 km, time t = 11 hours. You are asked for the speed v.
2
Use the formula speed = distance ÷ time:
$v = \frac{d}{t} = \frac{20}{11} = \frac{20}{11} = 1.8181818$
3
Answer with the unit: 1.8181818 km/h.
4
The same formula rearranged: distance = speed × time (1.8181818 × 11 = 20 km) and time = distance ÷ speed (20 ÷ 1.8181818 = 11 hours).

LaTeX source of the formulas on this page

\[ v = \frac{d}{t} = \frac{20}{11} = 1.8181818\ \text{km/h} \]
\[ v = \frac{d}{t} = \frac{20}{11} = \frac{20}{11} = 1.8181818 \]

What is the speed if a car travels 20 km in 11 hours?

The average speed is 1.8181818 km/h.

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

5.4545455 km.