$A$ man swimming in a stream which flows at $1.5 \, km/hr$ finds that in a given time he can swim twice as far with the stream as he can against it. At what rate does he swim in still water? (in $km/hr$)

$A$ person can row a certain distance downstream in $6$ hours and return the same distance in $9$ hours. If the stream flows at the rate of $3$ $km/h$,find the speed of the person in still water (in $km/h$).

$A$ man can swim at the rate of $4\, km/h$ in still water. If the speed of the water is $2\, km/h$,then the time taken by him to swim $10\, km$ upstream is.........$h$.

$A$ man rows at $9 \frac{1}{3} \text{ km/h}$ in still water and finds that it takes him thrice as much time to row up than to row down the same distance in the river. The speed of the current is.......$\text{km/h}$

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

$A$ swimmer's speed in downstream is $11 \, km/h$ and speed of the stream is $1.5 \, km/h$. Find the upstream speed of the swimmer? (in $km/h$)