Train $A$ crosses a stationary Train $B$ in $50 \text{ seconds}$ and a pole in $20 \text{ seconds}$ with the same speed. The length of Train $A$ is $240 \text{ meters}$. What is the length of the stationary Train $B$ (in meters)?

$A$ truck covers $224 \ km$ in $4 \ hours$. The average speed of a bike is $\frac{1}{4}$ of the average speed of the truck. How much distance will the bike cover in $7 \ hours$? (in $km$)

$A$ $135\, m$ long train is running with a speed of $54\, km/h$. In what time will it pass a telegraph post? (in $seconds$)

$A$ train covers a distance between station $A$ and station $B$ in $45 \, min$. If the speed of the train is reduced by $5 \, km/h$,then the same distance is covered in $48 \, min$. The distance between stations $A$ and $B$ is? (in $km$)

$A$ 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 $\text{km/h}$?

$P$ and $Q$ are $27 \, km$ apart. Two trains with speeds of $24 \, km/h$ and $18 \, km/h$ respectively start simultaneously from $P$ and $Q$ and travel in the same direction. They meet at a point $R$ beyond $Q$. The distance $QR$ is (in $km$):