$A$ and $B$ walk around a circular track. They start at $8\, a.m.$ from the same point in opposite directions. $A$ and $B$ walk at a speed of $2\, \text{rounds per hour}$ and $3\, \text{rounds per hour}$ respectively. How many times shall they cross each other before $9.30\, a.m.$?

$A$ thief is stopped by a policeman from a distance of $150\, m$. When the policeman starts the chase,the thief also starts running. Assuming the speed of the thief as $7\, km/h$ and that of the policeman as $9\, km/h$,how far would the thief have run before he is overtaken by the policeman? (in $m$)

$A$ boy goes to his school from his house at a speed of $3 \text{ km/hr}$. If he takes $5 \text{ hours}$ in total for going and coming back,the distance between his house and school is (in $\text{km}$):

$A$ 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 $km/h$):

$A$ train is travelling at a rate of $45 \, km/hr$. How many seconds will it take to cover a distance of $\frac{4}{5} \, km$?

$A$ $280\,m$ long train is moving at a speed of $60\,km/h$. The time taken by the train to cross a platform $220\,m$ long is (in $seconds$):