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MGMAT Question

by umaa » Sun Dec 20, 2009 8:53 am
[spoiler]Below is what I did,
1*1/13*1/12 + 1/13*1*1/12 = 1/78

There are six ways for giving medicine. So, 1/78*6 = 1/13

But the answer is 1/7.

Any idea what did I do wrong? [/spoiler]
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by Ian Stewart » Sun Dec 20, 2009 9:34 am
That question is essentially identical to Q7 in the diagnostic test at the beginning of OG12. Two of the 14 people will be given one of the drugs, so the probability Don will be selected is 2/14 = 1/7.
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by umaa » Sun Dec 20, 2009 9:38 am
It says, one of the 14 patients have given 2 medicines. Thanks for the OG comparison. I'll look at the question.
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