47.
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A is 30% more efficient than B. How much time will they, working together, take to complete a job which A alone could have done in 23 days?
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11 days
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13 days
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|
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None of these
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Answer: Option B
Explanation:
Ratio of times taken by A and B = 100 : 130 = 10 : 13.
Suppose B takes x days to do the work.
Then, 10 : 13 :: 23 : x x =
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23 x 13
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x =
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299
|
.
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10
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10
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A's 1 day's work =
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1
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;
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23
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B's 1 day's work =
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10
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.
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299
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(A + B)'s 1 day's work =
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1
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+
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10
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=
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23
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=
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1
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.
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23
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299
|
299
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13
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Therefore, A and B together can complete the work in 13 days.
