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

$A$ train $125 \;m$ long passes a man,running at $5 \;km/hr$ in the same direction in which the train is going,in $10 \;seconds$. The speed of the train is (in $km/hr$):

$A$ train moves past a telegraph post and a bridge $264 \; m$ long in $8 \; seconds$ and $20 \; seconds$ respectively. What is the speed of the train (in $km/hr$)?

How long (in $seconds$) does a train $110 \; m$ long running at a speed of $72 \; km/hr$ take to cross a bridge $132 \; m$ in length?

Two trains of equal lengths take $10 \; s$ and $15 \; s$ respectively to cross a telegraph post. If the length of each train is $120 \; m$,in what time (in $s$) will they cross each other when travelling in opposite directions?

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