Question
The speed of a boat in still water is 40% higher than
the speed of the stream. The boat takes 4 hours to travel 96 km downstream. If the boat's speed in still water is decreased by (100/7)% , determine the distance the boat can cover upstream in 6 hours.Solution
ATQ, Let the speed of the stream be '10p' km/h. So, the speed of the boat in still water = 1.4 × 10p = '14p' km/h. According to the question, 14p + 10p = 96/4 Or, 24p = 24 Thus, 'p' = 1. The speed of the stream = 10p = 10 km/h. Now, the reduced speed of the boat in still water = 14p × (6/7) = 12 km/h. Therefore, the required distance = (12 - 10) × 6 = 12 km.
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