Question
A boat can travel 30 km downstream in 2 hours and return
upstream in 3 hours. What is the speed of the boat in still water?Solution
Downstream speed = Distance/Time = 30/2 = 15 km/h. Upstream speed = Distance/Time = 30/3 = 10 km/h. Let speed of the boat in still water be x and speed of the current be y. Then, x + y = 15, x - y = 10. Adding both equations: 2x = 25 → x = 12.5 km/h. Answer: c) 12.5 km/h.
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