Two trains are moving in the same direction at $50 \text{ km/hr}$ and $30 \text{ km/hr}$. The faster train crosses a man sitting in the slower train in $18 \text{ seconds}$. Find the length of the faster train in meters.

$A$ carriage driving in a fog passed a man who was walking at the rate of $3 \text{ km/h}$ in the same direction. He could see the carriage for $4 \text{ minutes}$ and it was visible to him up to a distance of $100 \text{ m}$. What was the speed of the carriage in $\text{km/h}$?

The ratio between the speed of a train and a car is $16: 15$. Also,a bus covered a distance of $480 \, km$ in $8 \, hours$. The speed of the bus is $\frac{3}{4}$ the speed of the train. How much distance will the car cover in $6 \, hours$? (in $km$)

$A, B$ and $C$ can walk at the rates of $3, 4$ and $5 \text{ km/h}$ respectively. They start from Pune at $1, 2$ and $3 \text{ o'clock}$ respectively. When $B$ catches $A$,$B$ sends him back with a message to $C$. When will $C$ get the message?

$A$ train is moving with a speed of $180 \, km/hr$. Its speed in $m/s$ is:

Two cars $P$ and $Q$ start at the same time from $A$ and $B$ which are $120 \, km$ apart. If the two cars travel in opposite directions,they meet after $1 \, hour$,and if they travel in the same direction (from $A$ towards $B$),then $P$ meets $Q$ after $6 \, hours$. What is the speed of car $P$ (in $km/hr$)?