Question
A boat can row to a place of 60km away and come back
in hours. The time to row 12 km with the stream is same as the time to row 8km against the stream. Find the speed of the current?Solution
Speed downstream = 12/x km/hr Speed upstream = 8/x km/hr According to the question, 60/(12/x) + 60/(8/x) = 25/2 60 (x/12+x/8) = 25/2 15 (x/3+x/2) = 25/2 x = 1 So, speed downstream = 12 km/hr Speed upstream = 8 km/hr Speed of current = 1/2 (12 – 8) = 2km/hrÂ
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