The definition of speed is $$\text{Speed} = \frac{\text{Distance Travelled}}{\text{Time Taken}}$$. So, to calculate the speed, you measure the distance an object has travelled, and divide it by the time required for the object to travel that distance.
If Jerry is driving a car and he travels $$50 \, \mathrm{metres}$$ in $$10 \, \mathrm{seconds}$$, what is his speed?
• $$5$$ metres per second
• $$500$$ metres per second
• $$0.5$$ metres per second
• $$50$$ metres per second