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:

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.

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

Two trains running in opposite directions cross a man standing on the platform in $27 \;seconds$ and $17 \;seconds$ respectively, and they cross each other in $23 \;seconds$. The ratio of their speeds is

Two trains are running at $40 \; km/hr$ and $20 \; km/hr$ respectively in the same direction. The faster train completely passes a man in the slower train in $5 \; seconds$. What is the length (in $m$) of the faster train?

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 $m$).