arithmetic - a boy takes thrice 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 - skillgun

Let boys rate upstream be x km/hr. then, his rate downstream - 3x km/hr
.'. (speed in still water) : (speed of stream) = (3x+x)/2 : (3x -x)/2 = 4 : 2
= 2 : 1