$A$ boatman rows $1\, km$ in $5\, min$ along the stream and $6\, km$ in $1\, h$ against the stream. The speed of the stream is in $km/h$:

$A$ river is flowing at a speed of $5\, km/h$ in a particular direction. $A$ man,who can swim at a speed of $20\, km/h$ in still water,starts swimming along the direction of flow of the river from point $A$ and reaches another point $B$ which is at a distance of $30\, km$ from the starting point $A$. On reaching point $B$,the man turns back and starts swimming against the direction of flow of the river and stops after reaching point $A$. The total time taken by the man to complete his journey is:

The speed of a boat in still water is $7\, km/h$. If its speed in downstream is $10\, km/h$,then the speed of the stream is .......... $km/h$.

$A$ boat moves downstream at the rate of $1 \, km$ in $7 \frac{1}{2} \, \text{minutes}$ and upstream at the rate of $5 \, km/h$. What is the speed (in $km/h$) of the boat in still water?

Rohit can row a certain distance downstream in $8$ $hours$ and return the same distance in $12$ $hours$. If the stream flows at the rate of $5$ $km/hr$,find the speed of Rohit in still water (in $km/hr$).

The speed of a boat in still water is $6\, km/hr$ and the speed of the stream is $1.5\, km/hr$. $A$ man rows to a place at a distance of $22.5\, km$ and comes back to the starting point. The total time taken by him is