$A$ man can row at $5 \text{ km/hr}$ in still water. If the velocity of the current is $1 \text{ km/hr}$ and it takes him $1 \text{ hour}$ to row to a place and come back,how far is the place? (in $\text{km}$)

$A$ man can row $30 \text{ km}$ downstream and return in a total of $8 \text{ h}$. If the speed of the boat in still water is $4$ times the speed of the current,then the speed of the current is ....... $\text{km/h}$.

$A$ boat covers $12\, km$ upstream and $18\, km$ downstream in $3\, hours,$ while it covers $36\, km$ upstream and $24\, km$ downstream in $6\frac{1}{2}\, hours.$ What is the speed of the current? (in $km/h$)

$A$ 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 can row a boat at a speed of $8\, km/h$ in still water. He was rowing the boat downstream from one point to another. After travelling half of the distance,the motor of the boat failed. He continued to drift along the stream and reached his destination,taking $6\, hours$ more than the usual time. The speed of the stream is $2\, km/h$. What is the total distance between the two points in $km$?

The ratio of the speed of a motorboat to that of the water current is $36 : 5$. The motorboat travels along with the current in $5 \, h \, 10 \, min$. Find the time taken by the motorboat to return.