Question
The ratio of the speed of boat ‘A’ in still water,
the speed of boat ‘B’ in still water and the speed of the current is 8:6:2, respectively. If the time taken by boat ‘A’ to travel (5D – 15) km downstream is equal to the time taken by boat ‘B’ to travel (D + 70) km upstream, then find the value of ‘D’.Solution
Let, the speeds of boat ‘A’ and boat ‘B’, in still water and the speed of the current be 8x km/hr, 6x km/hr and 2x km/hr, respectively. According to the question, (5D – 15)/(8x + 2x) = (D + 70)/(6x – 2x) Or, 20D – 60 = 10D + 700 Or, 10D = 760 Or, D = 76
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