$A$ man swims downstream a distance of $15\, km$ in $1\, h$. If the speed of the current is $5\, km/h$,the time taken by the man to swim the same distance upstream is

$A$ boat travels upstream from $B$ to $A$ and downstream from $A$ to $B$ in $3$ $hours$. If the speed of the boat in still water is $9\, km/h$ and the speed of the current is $3\, km/h$, find the distance between $A$ and $B$ in kilometres.

$A$ person takes total $5$ $hours$ to go to a destination downstream and come back upstream by boat. If the speed of the boat in still water is $10 \text{ km/h}$ and the speed of the stream is $4 \text{ km/h}$,what is the distance of the destination from the starting point (in $\text{km}$)?

$P, Q, R$ are three towns on a river which flows uniformly. $Q$ is equidistant from $P$ and $R$. $A$ man rows from $P$ to $Q$ and returns in $10 \, h$. He can row from $P$ to $R$ in $4 \, h$. The ratio of the speed of the man in still water to the speed of the current is

In a stream running at $2 \, km/h$,a motorboat goes $10 \, km$ upstream and returns to the starting point in $55 \, min$. Find the speed of the motorboat in still water (in $km/h$).

Speed of boat in still water is $5\, km/h$. While river is flowing with a speed of $2\, km/h$ and time taken to cover a certain distance upstream is $2\, h$ more than time taken to cover the same distance downstream. Find the distance (in $km$).