Q. A man can swim at the rate of 4 km/hr in still water. If the speed of the water is 2 km/hr, then the time taken by him to swim 10 km upstream is :
Answer: $latex 5 hrs$
Notes: Rate upstream = 4 - 2 = 2 km/hr ∴ Required Time $latex = \frac{10}{2} = 5 hours&s=1$ Hence option [D] is correct answer.

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