$A$ 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 .......... $km/h$.

Two boats $A$ and $B$ start towards each other from two places,$108 \text{ km}$ apart. The speeds of boats $A$ and $B$ in still water are $12 \text{ km/h}$ and $15 \text{ km/h}$,respectively. If $A$ proceeds down the stream and $B$ proceeds up the stream,they will meet after .......... $\text{h}$.

$A$ river is flowing with a steady speed of $4\, km/h$. One rows his boat downstream in the river and then returns by rowing upstream in the same river. When he returns to the starting point,the total distance covered by him is $42\, km$. If the return journey takes $2\, h$ more than his outward journey,then the speed of his rowing in still water must be (in $km/h$)

The speed of a boat in still water is $7\, km/h$. If its speed in downstream is $10\, km/h$,then the speed of the stream is .......... $km/h$.

$A$ boat goes $48\, km$ downstream in $20\, h$. It takes $4\, h$ more to cover the same distance against the stream. What is the speed of the boat in still water? (in $km/h$)

$A$ man can row three-quarters of a kilometre against the stream in $11 \frac{1}{4}$ minutes. The speed (in $km/hr$) of the man in still water is