<PRE><B>Question 481427</B>
Let still water paddle speed : x km

Since stream current is 2 km per hour, therefore
upstream speed = x-2   and downstream speed = x+2

Time taken : distance/speed

Upstream : 24/(x-2)
Downstream : 24/(x+2)

The problem states that it takes three hours less time to paddle same distance downstream than same distance upstream.

Accordingly

24/(x-2)  - 24/(x+2)=3

Solving above for x results in x=6

Ans : still water paddle speed : 6 km








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