If a man's rate with the current is $12 \text{ km/h}$ and the rate of the current is $1 \frac{1}{2} \text{ km/h}$,then his rate against the current is ...... $\text{km/h}$.

$A$ boat goes $2\, km$ upstream and $3\, km$ downstream in $20$ minutes. It goes $7\, km$ upstream and $2\, km$ downstream in $53$ minutes. What is the speed (in $km/hr$) of the boat in still water?

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 $km/h$)

$A$ boat covered a certain distance travelling downstream in $45$ $minutes,$ while it came back to the starting point in $1$ $hour$ $15$ $minutes.$ The speed of the stream is $2$ $kmph.$ What is the speed of the boat in still water? (in $kmph$)

$A$ 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 $km/h$)

$A$ 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