Answer:
v = d/t, perhaps.
Explanation:
Velocity (speed) is defined as distance traveled divided by the time it takes to travel that distance.
This gives an average speed. For example, I'll be taking a trip tomorrow of about 150 miles. If it takes me 3 hours, my average speed is v = 150/3 = 50 miles per hour.
That does not mean my speed is constantly 50 miles per hour; I sometimes go slower than that (maybe even stopping for red lights!), and sometimes I'll be going faster than that.
A lot of school math problems assume a constant speed.