What time will be taken by a boat to cover a distance of $128\, km$ along the stream,if the speed of a boat in still water is $24\, km/h$ and the speed of the stream is $8\, km/h$? (in $h$)

The speed of a boat in still water is $4 \, km/h$ and the speed of the current is $2 \, km/h$. If the time taken to reach a certain distance upstream is $9 \, hours$,find the time it will take to go the same distance downstream (in $hrs$).

$A$ motor-boat,travelling at the same speed,can cover $25\, km$ upstream and $39\, km$ downstream in $8\, hours$. At the same speed,it can travel $35\, km$ upstream and $52\, km$ downstream in $11\, hours$. The speed of the stream is $........\, km/h$.

The speed of a boat in still water is $6\, km/h$ and the speed of the stream is $1.5\, km/h$. $A$ man rows to a place at a distance of $22.5\, km$ and comes back to the starting point. Find the total time taken by him (in $hours$).

$A$ man's speed with the current is $15 \, km/hr$,and the speed of the current is $2.5 \, km/hr$. The man's speed against the current is.......$km/hr$

Speed of a motorboat in still water is $45 \text{ km/h}$. If the motorboat travels $80 \text{ km}$ along the stream in $1 \text{ h } 20 \text{ min}$,then the time taken by it to cover the same distance against the stream will be: