Solved UPSC CDS/OTA Question
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Q · Boat and StreamModerate · 45s
For the same distance, time downstream : upstream = 2 : 5. If stream speed is 3 km/h, find the boat's still water speed.
TopicBoat and Stream
Question Typemultiple choice
DifficultyModerate
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained - no skipped algebra.
(u-v)/(u+v) = 2/5 ⇒ 5u - 5v = 2u + 2v ⇒ 3u = 7v ⇒ u = 7v/3 = 7.0 km/h.
Final Answer: Option B - 7 km/h