A boatman starts from point A at 11:00 am and travels downstream to point B, stays there for an hour and returns to point A at 4:00 pm. If the speed of the boat and stream are
A
45 km
B
22.5 km
C
36 km
D
27 km
Correct Option - D
Explaination
Upstream and downstream travel took him 4 hours (leaving his 1 hour stay at B).
u = 9 km/hr
d = 15 km/hr
(x/9) + (x/15) = 4
Distance = 22.5 km