A boat travels 24 km upstream and 36 km downstream in 6 hours. If the speed of the stream is 2 km/h, find the speed of the boat in still water.
A8 km/h
B10 km/h
C12 km/h
D14 km/h
Explanation
Let speed in still water be v. Upstream speed = v – 2, downstream speed = v + 2. Time: 24/(v-2) + 36/(v+2) = 6. Test v = 10: 24/8 + 36/12 = 3 + 3 = 6. So v = 10 km/h.
Exam Relevance
- Topic: Speed, Time & Distance
- Subtopic: Boats and Streams
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