A man can swim at the rate of 3 km/hr. in still water. Then, if speed of the stream is 2 km/hr., then in what time he will cover a total distance of 5 km in with the stream and against the stream?
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4(2/3) hours
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5 hours
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6 hours
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4(1/6) hours
C
Correct answer
Explanation
Downstream speed = 3 + 2 = 5 km/h, upstream speed = 3 - 2 = 1 km/h. Time to go 5 km downstream and 5 km upstream: 5/5 + 5/1 = 1 + 5 = 6 hours. Note: the wording is unclear but 'with and against the stream' implies going with the stream and then returning against it.