$A$ car covers four successive $3 \, km$ stretches at speeds of $10 \, km/h$,$20 \, km/h$,$30 \, km/h$,and $60 \, km/h$ respectively. Its average speed over this total distance is (in $km/h$):

$A$ train,$240 \, m$ long,crosses a man walking along the line in the opposite direction at the rate of $3 \, km/h$ in $10 \, seconds$. The speed of the train is (in $km/h$):

$A$ car travels the first $39 \, km$ distance in $45 \, minutes$ and the next $25 \, km$ distance in $35 \, minutes$. What is its average speed in $km/h$?

Two trains,each of length $125 \, m$,are running on parallel tracks in opposite directions. One train is running at a speed of $65 \, km/h$ and they cross each other in $6 \, s$. The speed of the other train is (in $km/h$):

Two trains,$A$ and $B,$ start from stations $X$ and $Y$ towards $Y$ and $X$ respectively. After passing each other,they take $4\, \text{hours } 48\, \text{minutes}$ and $3\, \text{hours } 20\, \text{minutes}$ to reach $Y$ and $X$ respectively. If train $A$ is moving at $45\, \text{km/h},$ then the speed of train $B$ is (in $\text{km/h}$)

Compare the speed of two trains,one moving at the speed of $80 \, km/h$ and the other at $10 \, m/s$.