$A$ body moves with velocities $v$,$2v$,and $3v$ in the first,second,and third one-third distances of the path traveled,respectively. Its average speed is:

$A$ man walks on a straight road from his home to a market $2.5 \; km$ away with a speed of $5 \; km \; h^{-1}$. Finding the market closed,he instantly turns and walks back home with a speed of $7.5 \; km \; h^{-1}$. What is the average speed of the man over the interval of time $0$ to $30 \; min$?

$A$ car travels from point $A$ to point $B$ with a speed of $40 \ km/h$ and returns from $B$ to $A$ with a speed of $60 \ km/h$. What is the average speed of the car for the entire journey (in $km/h$)?

Consider a particle moving along a straight line, whose position as a function of time is given by $s(t) = \alpha t^2 - \beta t + \gamma$, where $\alpha = 1 \text{ ms}^{-2}$, $\beta = 6 \text{ ms}^{-1}$ and $\gamma = 5 \text{ m}$. The average speed of the particle, in $\text{ms}^{-1}$, from $t = 0$ to $t = 6 \text{ s}$ is :

$A$ particle moves with constant speed $v$ along a regular hexagon $ABCDEF$ in the same order. What is the magnitude of the average velocity for its motion from $A$ to $F$?

$A$ 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