$A$ train covers a distance of $12 \;km$ in $10 \;minutes$. If it takes $6$ seconds to pass a telegraph post,then the length of the train (in $m$) is:

Two trains running at the rate of $45 \; km/h$ and $36 \; km/h$ respectively,on parallel tracks in opposite directions,are observed to pass each other in $8 \; seconds$. When they are running in the same direction at the same rate as before,a person sitting in the faster train observes that he passes the other in $30 \; seconds$. Find the length of the trains (in $m$).

$A$ train $360 \; m$ long is running at a speed of $45 \; km/hr$. In what time (in $sec$) will it pass a bridge $140 \; m$ long?

How many seconds will a $500 \;m$ long train take to cross a man walking with a speed of $3 \;km/h$ in the same direction as the moving train,if the speed of the train is $63 \;km/h$?

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

$A$ train $800 \; m$ long is running at a speed of $78 \; km/hr$. If it crosses a tunnel in $1 \; minute$,then the length (in $m$) of the tunnel is: