The current of a stream runs at $1 \, km/h$. $A$ motor boat goes $35 \, km$ upstream and back again to the starting point in $12 \, hours$. The speed of the motor boat in still water in $km/h$ is:

The speed of a boat in still water is $9\, km/h$ and the speed of the stream is $1.5\, km/h$. $A$ man rows to a place at a distance of $105\, km$ and comes back to the starting point. What is the total time taken by him?

$P$,$Q$,and $R$ are three towns on a river that flows uniformly. $Q$ is equidistant from $P$ and $R$. $I$ row from $P$ to $Q$ and back in $10$ $hours$,and $I$ can row downstream from $P$ to $R$ in $4$ $hours$. Compare the speed of my boat in still water with that of the river.

The speed of a boat in still water is $10\, km/h$. It covers an upstream distance of $45\, km$ in $6\, h$. The speed (in $km/h$) of the stream is:

$A$ boat takes $3$ $hours$ to travel from place $M$ to $N$ downstream and back from $N$ to $M$ upstream. If the speed of the boat in still water is $4$ $km/h$,what is the distance between the two places? (in $km$)

Speed of a man is $12 \text{ km/h}$ in still water. If the rate of current is $4 \text{ km/h}$,then the effective speed of the man upstream is ......... $\text{km/h}$.