If you know the position vectors of a particle at two points along its path and also know the time interval
during which it moved from one point to the other, can you determine the particleâ€™s instantaneous velocity?
Its average velocity? Explain

The particle's instantaneous velocity cannot be determined; however, its average velocity can be determined given the position vectors of a particle at two points along its path and the time interval
during which it moved from one point to the other.

The average velocity can be determined since we already know the time interval and the displacement.