In what time (in $sec$) will a train $100 \; m$ long cross an electric pole,if its speed is $144 \; km/hr$?

Two trains of equal length are running on parallel tracks in the same direction at $46 \; km/h$ and $36 \; km/h$ respectively. The faster train passes the slower train in $36 \; seconds$. The length (in $m$) of each train is:

How many seconds will a train $60 \; m$ in length,travelling at the rate of $42 \; km/h$,take to pass another train $84 \; m$ long,proceeding in the same direction at the rate of $30 \; km/h$?

$A$ train covers a distance between two stations $A$ and $B$ in $45$ minutes. If the speed is reduced by $5 \; km/h$,it will cover the same distance in $48$ minutes. What is the distance between the two stations $A$ and $B$ (in $km$)? Also,find the speed of the train.

Two trains $140 \; m$ and $160 \; m$ long run at a speed of $60 \; km/hr$ and $40 \; km/hr$ respectively in opposite directions on parallel tracks. The time (in $seconds$) which they take to cross each other is:

The length (in $m$) of the bridge,which a train $130 \; m$ long and travelling at $45 \; km/hr$ can cross in $30 \; s$,is: