A man can row 6 km/h in still water. If the river flows at 2 km/h, it takes him 3 hours to row to a place and back. How far is the place?
A6 km
B8 km
C10 km
D12 km
Explanation
Downstream speed = 6 + 2 = 8 km/h. Upstream speed = 6 – 2 = 4 km/h. Time: d/8 + d/4 = 3 => (d + 2d) / 8 = 3 => 3d / 8 = 3 => d = 8 km.
Exam Relevance
- Topic: Speed, Time & Distance
- Subtopic: Boats and Streams
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