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Odd Problem

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by knight247 » Sun Sep 18, 2011 4:17 am
If a number is drawn at random from the first 1000 positive integers, what is the probability of selecting a refined number?
(1)Any refined number must be divisible by 22
(2)A refined number is any even multiple of 11
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Source: — Data Sufficiency |
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by mehrasa » Sun Sep 18, 2011 4:48 am
I did not solve the problem mathematically.. but i think each statement alone is sufficient... since both set of refined No. are the same and we can find out the number of ech even to find the probability
IMO:D
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by sl750 » Sun Sep 18, 2011 5:26 am
Statement 1

Refined numbers could be 22,44,66.....990 We can find the probability of selecting a refined number. Sufficient

Statement 2

Even multiples of 11 are 22, 44, 66...This is the same as statement 1. Sufficient
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by gmatboost » Tue Sep 20, 2011 8:20 pm
The GMAT would never use an unknown term in a question without defining it in the question itself.

I would answer B to this question, but it is a matter of being very picky about the language and has nothing do to with math, so this is not really a GMAT math question.
(1)Any refined number must be divisible by 22
This doesn't actually say that a refined number is a multiple of 22. It says it MUST be a multiple of 22, but there might be other conditions we don't know about.

(2)A refined number is any even multiple of 11
This actually says that a refined number is a multiple of 22.

Again, not really a GMAT question.
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by Brent@GMATPrepNow » Wed Sep 21, 2011 6:35 am
This would be closer to an actual GMAT question if there were some wording in the question stem explaining that "refined numbers" is a fictitious term.

I also have a problem with the term "even multiple." Although the definition might be intuitively apparent, I believe the GMAT test-makers would provide additional text to avoid any ambiguity.

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