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 running upstream takes $8$ $hours$ $48$ $minutes$ to cover a certain distance,while it takes $4$ $hours$ to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the current respectively?

$A$ man rows to a place $48 \, km$ away and comes back in $14 \, hours$. He finds that he can row $4 \, km$ with the stream in the same time as $3 \, km$ against the stream. The rate of the stream is:

$A$ man can row at $5 \, km/h$ in still water and the velocity of the current is $1 \, km/h$. It takes him $1 \, hour$ to row to a place and back. How far is the place? (in $km$)

$A$ boat travels $32 \ km$ downstream in $4 \ hours$ and $24 \ km$ upstream in $6 \ hours$. What is the speed (in $km/hr$) of the boat in still water?

If the speed of a boat in still water is $20\, km/hr$ and the speed of the current is $5\, km/hr$,then the time taken by the boat to travel $100\, km$ with the current is......$hours$.