Question
A boat goes 24 km downstream in 2 hours and comes back
the same distance upstream in 3 hours. Find the speed of the boat in still water and the speed of the stream.Solution
Downstream speed = 24/2 = 12 km/h Upstream speed = 24/3 = 8 km/h Let boat speed in still water = u, stream speed = v. u + v = 12 u − v = 8 Add: 2u = 20 ⇒ u = 10 km/h Then v = 12 − 10 = 2 km/h Answer: Boat speed = 10 km/h, stream speed = 2 km/h.
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