$A$ car moving on a straight road covers one-third of the distance with $20 \, km/hr$ and the rest with $60 \, km/hr$. The average speed is .......... $km/hr$.

$A$ particle moves along a straight line along the $x$-axis. Its position $(x)$ versus time $(t)$ graph is shown in the figure [$x$ in meters and $t$ in seconds]. Its average speed during this motion is (in $\text{ m/s}$)

$A$ particle covers half of its total distance with speed $v_1$ and the rest half distance with speed $v_2$. Its average speed during the complete journey is

$A$ particle moves along a semicircle of radius $10\,m$ in $5$ seconds. The average velocity of the particle is...........$m/s$.

$A$ train travels from city-$A$ to city-$B$ with a constant speed of $18 \,ms^{-1}$ and returns back to city-$A$ with a constant speed of $36 \,ms^{-1}$. Find its average speed during the journey. (in $\,ms^{-1}$)

$A$ bus travels the first one-third distance at a speed of $10\; km/h$,the next one-third at $20\; km/h$,and the last one-third at $60\; km/h$. The average speed of the bus is ........ $km/h$.