A man can row a boat with a speed of 6\(\frac{3}{5}\) km. in still water. He finds out that he takes twice of the time in going against the stream than going with the stream. Accordingly, what is the speed of stream?

2\(\frac{1}{5}\)

 ∴ If distance is same then, ratio of speed =  \(\frac{1}{ratio of time}\)

ATQ,             Downstream (D.S)   :         Upstream (U.S) 

        Time →                    1           :            2

       Speed →                   2          :            1

         Boat Speed          :             Stream Speed

               \(\frac{D.S + U.S}{2}\)        :          \(\frac{D.S - U.S}{2}\)         

                     \(\frac{2 + 1}{2}\)        :          \(\frac{2 - 1}{2}\)

                            3       :           1

                     x\(\frac{11}{5}\) ↓                  ↓  x\(\frac{11}{5}\)

          (given) \(\frac{33}{5}\) km/hr            2\(\frac{1}{5}\)