20km in 1 hour as a rate (fraction) is = 20km/1hr = 20km/hr.
Note in everyday life we express speed as a ratio of distance traveled per unit time, so 20km/hr is usually the way we would express the rate in this example.
But there might be applications where we wanted to use an expression for the amount of time it would take to go a certain distance; so with this example we could also express the rate (fraction) as .
The usual rate tells us we go 20km in 1 hour; this rate would tell us that it takes 1/20 hour to go 1 kilometer.
