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:

$A$ train is moving at a speed of $120 \; km/hr$. If the length of the train is $120 \; m$,how long will it take to cross a railway platform $130 \; m$ long (in $sec$)?

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?

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

Two trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after $9 \; \text{hours}$ and $16 \; \text{hours}$ respectively. The ratio of their speeds is