$A$ car moves for half of its time at $80 \, km/h$ and for the rest half of the time at $40 \, km/h$. The total distance covered is $60 \, km$. What is the average speed of the car in $km/h$?

$A$ train has a speed of $60\, km/h$ for the first one hour and $40\, km/h$ for the next half hour. Its average speed in $km/h$ is

$A$ body travelling along a straight line path travels the first half of the distance with a velocity of $7 \,m/s$. During the travel time of the second half of the distance, the first half of the time is travelled with a velocity of $14 \,m/s$ and the second half of the time is travelled with a velocity of $21 \,m/s$. Then the average velocity of the body during the entire journey is: (in $\,m/s$)

$A$ body covers half of its distance with speed $u$ and the other half with a speed $v$,the average speed of the body is

$A$ body covers the first one-third of the distance with a velocity of $20 \, m/s$,the second one-third with a velocity of $30 \, m/s$,and the last one-third with a velocity of $40 \, m/s$. The average velocity is nearly........$m/s$.

$A$ vehicle travels $4\,km$ with a speed of $3\,km/h$ and another $4\,km$ with a speed of $5\,km/h$. What is its average speed in $km/h$?