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)?

Two trains,Kanpur Mail and Delhi Mail,start at the same time from stations Kanpur and Delhi respectively towards each other. After passing each other,they take $12\, \text{hours}$ and $3\, \text{hours}$ to reach Delhi and Kanpur respectively. If the Kanpur Mail is moving at the speed of $48\, \text{km/hr}$,the speed of the Delhi Mail is (in $\text{km/hr}$):

$A$ and $B$ walk around a circular track. They start at $8\, a.m.$ from the same point in opposite directions. $A$ and $B$ walk at a speed of $2\, \text{rounds per hour}$ and $3\, \text{rounds per hour}$ respectively. How many times shall they cross each other before $9.30\, a.m.$?

$A$ train starts from Delhi on Sunday at $9 \, am$ with a speed of $25 \, km/h$. Another train starts from the same place on the same day at $3 \, pm$ with a speed of $40 \, km/h$ in the same direction. Find at what distance from Delhi both trains will meet? (in $km$)

The bus fare for one person is $Rs. 420$ from Agra to Aligarh and the train fare between the same places for one person is equal to $\frac{3}{4}$ of the bus fare for $2$ persons between the same places. What is the total fare paid by $2$ persons traveling by bus and $4$ persons traveling by train between the two places? (in $Rs.$)

$A$ train $150 \, m$ long takes $20 \, s$ to cross a platform $450 \, m$ long. The speed of the train in $km/h$ is: