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 goods trains,each $500 \; m$ long,are running in opposite directions on parallel tracks. Their speeds are $45 \; km/hr$ and $30 \; km/hr$ respectively. Find the time (in $seconds$) taken by the slower train to pass the driver of the faster one.

$A$ $270 \;m$ long train running at a speed of $120 \;km/hr$ crosses another train running in the opposite direction at a speed of $80 \;km/hr$ in $9 \;seconds$. What is the length (in $m$) of the other train?

$A$ $300 \;m$ long train crosses a platform in $39 \;seconds$,while it crosses a signal pole in $18 \;seconds$. What is the length of the platform? (In $m$)

$A$ 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 are moving in opposite directions at $60 \; km/hr$ and $90 \; km/hr$ respectively. Their lengths are $1.1 \; km$ and $0.9 \; km$ respectively. The time taken by the slower train to cross the faster train in seconds is