$A$ 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

Five particles have speeds $1, 2, 3, 4, 5 \, m/s$. The average velocity of the particles is (in $m/s$):

$A$ particle moves in the east direction with $15 \, m/s$ for $2 \, s$,then moves northward with $5 \, m/s$ for $8 \, s$. The average velocity of the particle is:

$A$ car travels from $A$ to $B$ at a speed of $20\,km/hr$ and returns at a speed of $30\,km/hr$. The average speed of the car for the whole journey is............$km/hr$

Define speed. Define average speed.

$A$ 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 $\,m/s$)