P, Q and R are three towns on a River which flows uniformely. Q is equidistance from P and R. A man rows from P to Q and return in 10 hour. He can row P to R in downstream in 4 hour. Find the Ratio of speed of man in still water to that of current(River).

• A. 3 : 5
• B. 5 : 3
• C. 1 : 2
• D. 2 : 1
• E. None of the above