Two men are standing on opposite ends of a bridge of $1200 \, m$ long. If they walk towards each other at the rate of $5 \, m/min$ and $10 \, m/min$ respectively,in how much time will they meet each other? (in $minutes$)

$A$ train running at the speed of $84 \, km/h$ passes a man walking in the opposite direction at the speed of $6 \, km/h$ in $4 \, s$. What is the length of the train (in $meters$)?

Two trains,one $160 \, m$ and the other $140 \, m$ long,are running in opposite directions on parallel tracks. The first is moving at $77 \, km/h$ and the other at $67 \, km/h$. How long will they take to cross each other? (in $seconds$)

$A$ car covers a distance of $330 \, km$ in a certain amount of time at a speed of $55 \, km/h$. What is the average speed of a bike that covers a distance of $15 \, km$ less than the car in $1 \, hour$ less than the time taken by the car? (in $km/h$)

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

Two trains of equal length take $10\, seconds$ and $15\, seconds$ respectively to cross a telegraph post. If the length of each train is $120\, metres,$ in what time (in $seconds$) will they cross each other when travelling in opposite directions?