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

Deepa drives a bike at an average speed of $30 \, km/h$ and reaches her destination in $6 \, hours$. Hema covers that same distance in $4 \, hours$. If Deepa increases her average speed by $10 \, km/h$ and Hema increases her average speed by $5 \, km/h$,then what will be the difference in time taken by them to reach their destination?

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 $\text{km/hr}$):

In a flight of $600 \, km$,an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by $200 \, km/hr$ and the time of flight increased by $30 \, minutes$. The duration of the flight is (in $hour$):

$A$ $75 \, m$ long train is moving at $20 \, km/h$. It will cross a man standing on the platform in (in $sec$):

$A$ train crosses a platform in $30 \, s$ travelling with a speed of $60 \, km/h$. If the length of the train is $200 \, m$, then the length of the platform is (in $m$):