$A$ $100\, m$ long train passes a bridge at the rate of $72\, km/h$ in $25\, s$. What is the length of the bridge (in $m$)?

Two trains start at the same time from two stations and proceed towards each other at the speeds of $20 \, km/h$ and $25 \, km/h$ respectively. When they meet,it is found that one train has travelled $80 \, km$ more than the other. Find the distance between the two stations (in $km$).

$A$ truck covers a distance of $550\, m$ in $1\, minute,$ whereas a bus covers a distance of $33\, km$ in $45\, minutes.$ The ratio of their speeds is

$A$ motorcyclist travels from Mumbai to Pune,a distance of $192 \, km$,at an average speed of $32 \, km/h$. Another man starts from Mumbai by travelling in a car,$2 \frac{1}{2} \, hours$ after the motorcyclist and reaches Pune half an hour earlier. What is the ratio of the speeds of the motorcycle and the car?

$A$ person travels from $P$ to $Q$ at a speed of $40 \, km/hr$ and returns by increasing his speed by $50 \%$. What is his average speed for both the trips? (in $km/hr$)

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 $\text{km/hr}$):