The length (in $m$) of the bridge,which a train $130 \; m$ long and travelling at $45 \; km/hr$ can cross in $30 \; s$,is:

$A$ train $75 \; m$ long overtook a person who was walking at the rate of $6 \; km/h$ and passed him in $7 \frac{1}{2}$ seconds. Subsequently,it overtook a second person,and passed him in $6 \frac{3}{4}$ seconds. At what rate (in $km/h$) was the second person travelling?

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

$A$ train $100 \; m$ long is running at the speed of $30 \; km/hr$. Find the time (in $sec$) taken by it to pass a man standing near the railway line.

Two trains $100 \; m$ and $120 \; m$ long are running in the same direction with speeds of $72 \; km/h$ and $54 \; km/h$. In how much time will the faster train cross the second (in $; s$)?

$A$ 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 $sec$)?