From Figure below, $1)$ find the position vector at point A$,2)$ find the position vector at point B$,2)$ find the average speed of the particle that moves from origin to point B: started from the origin at time $=0$ sec$,$ then move to point A at time t $=2$ sec$,$ and then move to point B at time t$=4$ sec$,$ find the average velocity $3)$ from $2)$ find the average velocity of the particle that moves from point A to point B$.$

A$=-3$ B$=6$ on the number line