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Set -S

by iikarthik » Mon May 11, 2009 10:11 am
The set S of Numbers has the following properties:
i)if x is in S,then 1/x is in S
ii)If both x and y are in S,then so is x+y

is 3 in s?

1) 1/3 is in S

2) 1 is in S

[spoiler]
OS is D[/spoiler]
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Source: — Data Sufficiency |
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by cubicle_bound_misfit » Mon May 11, 2009 1:01 pm
Now stmt 1 is O.k.

but stmt 2 can be valid or invalid giving me two answers !!!

if 1 is in set so is its reciprocal 1.......the question is DO WE CONSIDER TWO IDENTICAL ELEMENTS OF A SET AS TWO DISTINCT ELEMENTS or ONE SINGLE ELEMENT

if two distinct element, 2 is suff
but if ther is only one entry for 1 then stmt 2 is not.

Gurus, Please help.
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by Ian Stewart » Mon May 11, 2009 6:17 pm
I find the wording of the question pretty ambiguous. It's not the kind of wording you'd find on a real GMAT question. The way property ii) in the stem is phrased seems intentionally misleading; because of the use of the word 'both', it seems to suggest that x and y are different elements in the set. If the OA is D, the clearly the intention is that x and y can be equal. If that statement were to appear in a real GMAT question, I'd expect the wording to be more like: "If x is in S, and if y is in S, then x+y is in S."
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