Raj and Prem walk in opposite directions at the rate of $3 \, km/h$ and $2 \, km/h$ respectively. How far will they be from each other after $2 \, hours$? (in $km$)

$A$ train $100 \, m$ long takes $3 \frac{3}{5} \, s$ to cross a man walking at the rate of $6 \, km/h$ in a direction opposite to that of the train. Find the speed of the train in $km/h$.

$A$ train $700 \, m$ long is running at a speed of $72 \, km/hr$. If it crosses a tunnel in $1 \, minute$,then the length of the tunnel (in $metres$) is:

Two trains,each of length $90\, m,$ run on parallel tracks. When running in the same direction,the faster train passes the slower train completely in $18\, s,$ but when they are running in opposite directions approaching each other at the same speeds as before,they cross each other in $9\, s.$ Find the speed of each train (in $m/s$).

$A$ policeman starts to chase a thief. When the thief goes $10 \, \text{steps}$, the policeman moves $8 \, \text{steps}$. $5 \, \text{steps}$ of the policeman are equal to $7 \, \text{steps}$ of the thief. The ratio of the speeds of the policeman and the thief is

It takes $24 \, s$ for a train travelling at $93 \, km/h$ to cross entirely another train half its length travelling in the opposite direction at $51 \, km/h$. It passes a bridge in $66 \, s$. What is the length of the bridge in meters?