A man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph, find his average speed for the total journey ?
Choose the correct option:  A) 1 kmph  B) 5 kmph  C) 6 kmph  D) 4 kmph  E) 7 kmph
Explanation:   Speed of Man = 4.5 kmph   Speed of stream = 1.5 kmph   Speed in DownStream = 6 kmph   Speed in UpStream = 3 kmph   Average Speed = (2 x 6 x 3)/9 = 4 kmph.   Answer: 4 kmph
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A man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph, find his average speed for the total journey ?