$A$ man can row $7\, km/hr$ in still water. If the river is running at $3\, km/hr$,it takes $6\, hours$ more to row upstream than to row downstream for the same distance. How far is the place? (in $km$)

In a fixed time,a boy swims double the distance along the current that he swims against the current. If the speed of the current is $3 \text{ km/h}$,then find the rate of swimming in still water in $\text{km/h}$.

$A$ man can swim $3 \text{ km/h}$ in still water. If the velocity of the stream is $2 \text{ km/h}$,the time taken by him to swim to a place $10 \text{ km}$ upstream and back is (in hours):

$A$ boat goes $20 \text{ km}$ downstream in $1 \text{ h}$ and the same distance upstream in $2 \text{ h}$. The speed of the boat in still water is ......... $\text{km/h}$.

$A$ man takes $3$ $hours$ $45$ $minutes$ to row a boat $15 \; km$ downstream of a river and $2$ $hours$ $30$ $minutes$ to cover a distance of $5 \; km$ upstream. Find the speed of the river current in $km/hr$.

The speed of a boat in still water is $4 \, km/h$ and the speed of the current is $2 \, km/h$. If the time taken to reach a certain distance upstream is $9 \, hours$,find the time it will take to go the same distance downstream (in $hrs$).