$A$ man can row $20 \text{ km/h}$ in still water and the speed of the stream is $5 \text{ m/s}$. The ratio of the speed of the man to the speed of the current is:

$A$ boatman can row $48\, km$ downstream in $4\, hours$. If the speed of the current is $5\, km/h$,then find in what time will he be able to cover $8\, km$ upstream? (in $hours$)

Aditya can row with the stream at $10 \text{ km/h}$ and against the stream at $6 \text{ km/h}$. His speed in still water is .......... $\text{km/h}$.

$P, Q, R$ 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

$A$ boat goes $14 \ km$ upstream in $42 \ minutes$. The speed of the stream is $4 \ km$. The speed of the boat in still water is .......... $km/h$.

$A$ motor boat,whose speed is $15 \text{ km/hr}$ in still water,goes $30 \text{ km}$ downstream and comes back in a total of $4 \text{ hours } 30 \text{ minutes}$. The speed of the stream (in $\text{km/hr}$) is: