Question
 A man can row the boat x km downstream and the same
distance upstream in 12 hours. Also, he can row the boat 5x km downstream in 10 hours. At what time, he can row the x km distance upstream?Solution
Let the downstream speed of the boat be ‘a’km/h According to the question, (5x/a) = 10 Or (x/a) = (10/5) Or (x/a) = 2 = time taken to travel ‘x’ km downstream Let the upstream speed of the boat be ‘b.’ km/h Also, (x/a) + (x/b) = 12 2 + x/b = 12 x / b = 10 hours
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