Ramesh sees a train passing over a $1 \, km$ long bridge. The length of the train is half that of the bridge. If the train passes the bridge in $2 \, minutes$,the speed of the train is (in $km/h$)

$A$ car travelling with $\frac{5}{7}$ of its actual speed covers $42 \, km$ in $1 \, hour \, 40 \, minutes \, 48 \, seconds.$ Find the actual speed of the car (in $km/hr$).

$A$ boy started from his house by bicycle at $10:00 \, am$ at a speed of $12 \, km/h$. His elder brother started after $1 \, hour \, 15 \, minutes$ by scooter along the same path and caught him at $1:30 \, pm$. The speed of the scooter was (in $km/h$):

$A$ thief is noticed by a policeman from a distance of $200\, m$. The thief starts running and the policeman chases him. The thief and the policeman run at the speed of $10\, km/h$ and $11\, km/h$ respectively. What is the distance between them after $6\, minutes$? (in $m$)

$A$ boy takes as much time in running $12 \, m$ as a car takes in covering $36 \, m$. The ratio of the speeds of the boy and the car is

$A$ man travelled from the village to the post office at the rate of $25 \, km/hr$ and walked back at the rate of $4 \, km/hr$. If the whole journey took $5 \, hours \, 48 \, minutes$,find the distance of the post office from the village (in $km$).