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 $75 \; m$ 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?

$A$ 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 $km/hr$)?

$A$ train $240 \; m$ long passed a pole in $24 \; s$. How long (in $s$) will it take to pass a platform $650 \; m$ long?

$A$ train $360 \; m$ long is running at a speed of $45 \; km/hr$. In what time (in $sec$) will it pass a bridge $140 \; m$ long?

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?