$A$ train covers a distance in $50 \text{ minutes}$ if it runs at a speed of $48 \text{ km/h}$. The speed at which the train must run to reduce the time of journey to $40 \text{ minutes}$ will be (in $\text{km/h}$):

$A$ bike covers a certain distance at a speed of $64 \, km/h$ in $8 \, hours$. If the bike were to cover the same distance in approximately $6 \, hours$,at what approximate speed should the bike travel? (in $km/h$)

$A$ passenger train $150 \ m$ long is travelling with a speed of $36 \ km/h$. If a man is cycling in the direction of the train at $9 \ km/h$,then the time taken by the train to pass the man is? (in $s$)

$A$ person travels $600 \, km$ by train at $80 \, km/hr$,$800 \, km$ by ship at $40 \, km/hr$,$500 \, km$ by aeroplane at $400 \, km/hr$,and $100 \, km$ by car at $50 \, km/hr$. What is the average speed for the entire distance? (in $km/hr$)

$A$ person covers a certain distance in $6 \, hours$ if he travels at $40 \, km/h$. If he has to cover the same distance in $4 \, hours$,then his speed must be (in $km/h$):

$A$ 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 $m$)