50.River
is running at 3 kmph. It takes a man twice as long to row up as to row down the
river. The rate of the man in still water is:
[A]
12
[C]
15
[B]
10
[D]
18
Answer : [A]
Explanation :
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Let
the rate upstream be x kmph
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rate
downstream = 2x kmph
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Rate
of current =
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1
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(2x - x)
kmph =
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x
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kmph
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2
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2
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x
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=
3 (or) x = 6
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Rate
upstream = 6 kmph
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2
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Rate
downstream = 12 kmph
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