Is the average of different speeds called average speed? Do you agree?

$A$ particle moving in a straight line covers half the distance with a speed of $3 \, m/s$. The other half of the distance is covered in two equal time intervals with speeds of $4.5 \, m/s$ and $7.5 \, m/s$ respectively. The average speed of the particle during this motion is...... $\, m/s$

$A$ vehicle runs on a straight road of length $L$. It travels half the distance with speed $V$ and the remaining distance with speed $\frac{V}{3}$. Its average speed is

If a person moving along a straight line path covers the first half distance with velocity $V_1$ and the next half distance with velocity $V_2$,then the average velocity of the person is

$A$ car travels a distance of $x$ with speed $v_1$ and then the same distance $x$ with speed $v_2$ in the same direction. The average speed of the car is

$A$ biker travels $\frac{1}{3}$ of the distance $L$ with speed $v_1$ and $\frac{2}{3}$ of the distance with speed $v_2$. Then the average speed is