$A$ man takes $6$ hours $30$ minutes in walking to a certain place and riding back. He would have gained $2$ hours $10$ minutes by riding both ways. How long would he take to walk both ways? (in minutes)

Train $A$ crosses a stationary Train $B$ in $50 \,s$ and a pole in $20 \,s$ with the same speed. The length of Train $A$ is $240 \,m$. What is the length of the stationary Train $B$ (in $m$)?

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 $km/h$):

$A$ 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 $meters$)?

$A$ thief is noticed by a policeman from a distance of $200\, m$. The thief starts running and the policeman chases him. The thief and the policeman run at the speed of $10\, km/h$ and $11\, km/h$ respectively. What is the distance between them after $6\, minutes$? (in $m$)

Two trains start at the same time from two stations and proceed towards each other at the speeds of $20 \, km/h$ and $25 \, km/h$ respectively. When they meet,it is found that one train has travelled $80 \, km$ more than the other. Find the distance between the two stations (in $km$).