$A$ train $200 \, m$ long is running at a speed of $20 \, m/s$. In how much time (in $seconds$) will it cross a bridge of $400 \, m$ length?

$A$ train is running at a uniform speed of $60 \, km/h$. It passes a railway platform in $15 \, s$. If the length of the platform is $130 \, m$,then the length of the train is (in $m$):

$A$ car completes a journey in $6\, hours$. It covers half the distance at $50\, km/h$ and the rest at $70\, km/h$. The length of the journey is (in $km$):

Rakesh sets out to cycle from Delhi to Mathura and at the same time Suresh starts from Mathura to Delhi. After passing each other,they complete their journeys in $9$ and $16 \, \text{hours}$,respectively. At what speed does Suresh cycle if Rakesh cycles at $16 \, \text{km/h}$?

Rajesh covers a certain distance by bus at $16 \text{ km/h}$ and returns to the starting point on a cycle at $9 \text{ km/h}$. His average speed for the whole journey is (in $\text{km/h}$):

$A$ 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 $km$)