$A$ man walking at the rate of $5\, km/hr$ crosses a bridge in $15\, minutes$. The length of the bridge (in $meters$) is:

How many $km/h$ does a man walk who passes through a street $600 \, m$ long in $5 \, minutes$?

$A$ man performs $\frac{2}{15}$ of the total journey by rail,$\frac{9}{20}$ by tonga,and the remaining $10 \ km$ on foot. The total journey is (in $km$):

$A$ man with $\frac{3}{5}$ of his usual speed reaches the destination $2 \frac{1}{2}$ hours late. Find his usual time to reach the destination? (in $hours$)

$A$ 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 $m$):

Two trains,one $160 \, m$ and the other $140 \, m$ long,are running in opposite directions on parallel tracks. The first is moving at $77 \, km/h$ and the other at $67 \, km/h$. How long will they take to cross each other? (in $seconds$)