$A$ motor car completes a journey in $10 \, hrs$. It covers the first half of the distance at $21 \, km/hr$ and the second half at $24 \, km/hr$. Find the total distance in $km$.

$A$ train can travel $50\%$ faster than a bus. Both start from point $A$ at the same time and reach point $B$ at the same time. Point $B$ is $75 \, km$ away from point $A$. On the way, the train stops for $12.5 \, minutes$. The speed of the bus is (in $km/h$):

$A$ train $150 \, m$ long is running at $95 \, km/h$. How much time will it take to pass a man moving in the same direction at $5 \, km/h$? (in $seconds$)

Supposing that telegraph poles on a railroad are $50 \, m$ apart,how many will be passed by a train in $4 \, hours$ if the speed of the train is $45 \, km/h$?

$A$ train $110 \, m$ long is running with a speed of $60 \, km/h$. In what time will it pass a man who is running at $6 \, km/h$ in the direction opposite to that in which the train is going? (in $seconds$)

Two trains of equal length take $10 \, s$ and $15 \, s$ respectively to cross a telegraph post. If the length of each train is $120 \, m$,in what time (in $s$) will they cross each other while travelling in the same direction?