A boatman rows 1 km in 5 minutes along the stream and 6 km in 1 hr against the stream. The speed of the stream is
Answer & explanation
Correct answer: option 3
Speed of boat in still water - x
Speed of stream/current - y
Downstream speed i.e. - x + y - \(\frac{1 }{5/60 }\) = 12 km/hr -----(1)
Upstream speed i.e. - x - y - \(\frac{6 }{1 }\) = 6 km/hr ---------(2)
Subtracting 2 from 1,
x + y - x + y = 6
2y = 6
y = 3km/hr