In a stream running at $2 \ km/h$,a motorboat goes $6 \ km$ upstream and back again to the starting point in $33 \ minutes$. Find the speed of the motorboat in still water. (in $km/h$)

$A$ 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 $km$)

$A$ boat running downstream covers a distance of $20\, km$ in $2\, h$ while it covers the same distance upstream in $5\, h$. Then,the speed of the boat in still water is ....... $km/h$.

From the given statements,decide which of the statement$(s)$ is/are necessary to answer the question.
What is the speed of a train?
$I.$ The length of the train is $240 \ m$.
$II.$ The train crosses a pole in $24 \ s$.
$III.$ The train crosses a platform in $48 \ s$.

$A$ 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......$km$.

$A$ man can row $9 \text{ km/hr}$ in still water. If the river is running at $3 \text{ km/hr}$,it takes $3 \text{ hours}$ more to row upstream than to row downstream for the same distance. How far is the place? (in $\text{km}$)