A man whose speed is 4 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1 kmph, find his average speed for the total journey ?  Choose the correct choice from the following choices
A) 1 kmph  B) 5 kmph  C) 6 kmph  D) 3.75 kmph  E) 7 kmph
Explanation:   Speed of Man = 4 kmph   Speed of stream = 1 kmph   Speed in DownStream = 5 kmph   Speed in UpStream = 3 kmph   Average Speed = (2 x 5 x 3)/8 = 3.75 kmph.   Answer: 3.75 kmph
<result>D</result>
A man whose speed is 4 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1 kmph, find his average speed for the total journey ?