Two trains,each $100 \; m$ long,moving in opposite directions,cross each other in $8 \; s$. If one is moving twice as fast as the other,then the speed (in $km/h$) of the faster train is:

$A$ 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?

$A$ jogger running at $9 \; km/hr$ alongside a railway track is $240 \; m$ ahead of the engine of a $120 \; m$ long train running at $45 \; km/hr$ in the same direction. In how much time (in $sec$) will the train pass the jogger?

$A$ $300 \;m$ 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 $m$)

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