Question
A swimmer swims from point P against the current for 6
minutes and then swims back along the current for the next 6 minutes and reaches point Q. If the distance between P and Q is 240 m then the speed of the current (in km/ h) is:Solution
Let the speed of boat in still water =B and speed of stream =S then Given-Time in Upstream and Downstream =6 min And Distance between P And Q =120m Speed of boat in Downstream =B+S Speed of boat in Upstream=B-S ATQ- 6(B+S)-6(B-S) =240 6B+6S-6B+6S=240 12S =240 S=20×60/1000 S= 0.12km/h
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