A man takes twice as long to row a distance against the stream as to row the same distance in favour of the stream. The ratio of the speed of the boat(in still water) and the stream is  Pick one
A) 1 : 2  B) 1 : 3  C) 2 : 1  D) 3 : 1  E) none

Rationale: "sol . let man ’ s rate upstream be x kmph . then , his rate downstream = 2 x kmph . ∴ ( speed in still water ) : ( speed of stream ) = [ 2 x + x / 2 ] : [ 2 x - x / 2 ] 3 x / 2 : x / 2 = 3 : 1 . answer d"
Answer: D