$A$ train is moving at a speed of $120 \; km/hr$. If the length of the train is $120 \; m$,how long will it take to cross a railway platform $130 \; m$ long (in $sec$)?

Two trains $250 \; m$ and $200 \; m$ long are running on parallel tracks at the rate of $36 \; km/hr$ and $45 \; km/hr$ respectively. In how much time (in $sec$) will they cross each other,if they are running in the same direction?

Two trains $100 \; m$ and $120 \; m$ long are running in the same direction with speeds of $72 \; km/h$ and $54 \; km/h$. In how much time will the faster train cross the second (in $; s$)?

$A$ train $280 \; m$ long, running with a speed of $63 \; km/hr$, will pass a tree in (in $sec$):

$A$ 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?

Length of a train and that of a platform are equal. If with a speed of $135 \; km/hr$,the train crosses the platform in $40 \; seconds$,then the length (in $m$) of the train is: