a

man leaves the garrage in his house and drives to a neigbouring town
which is twenty kilometres away from his house on sight-seeing. he
returns home to his garrag two hours after. what is his average velocity
from in home in km/h?

Assuming he travels in a straight line, the distance traveled in two hours is forty kilometres. The average _speed_ is 20km/hr.

Of course, he probably did not travel in a straight line.

In any case, the average velocity vector is [0,0,0]km/hr.