Hey there!
Speed is equal to distance/time. As much as you might not know, you've definitely seen this before. It's used in miled/hour and km/hr. The miles or kilometers are the distances, and the hours are the time.
We're not going to be able to get an exact speed because we don't have an exact distance, just a variable. We have:
Speed = d/t = d/16
The speed is d/16.
Hope this helps!