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agha79
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Are X and Y both positive?

by agha79 Sun Mar 20, 2011 12:18 pm

GMAT prep exam one question. I was unable to find this in the forms. I searched using first few words of the question as a search.

Are X and Y both positive?

1) 2x - 2y = 1
2) x/y > 1

I started with statement 2 for this one. For x/y to produce a result greater than one both X & Y either have to be positive or negative. Since this does not give a definitive answer we can cross of answer choice "B".

I picked multiple numbers for X & Y in statement "a" and concluded that for us to get a positive answer X & Y must be positive. I chose answer A but this is NOT correct. Please advise what my mistake was here.

OA: C
tim
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Re: Are X and Y both positive?

by tim Mon Mar 21, 2011 11:26 am

for statement 1, x could be 1/4 and y could be -1/4. in fact, anything where x is 1/2 more than y will work for statement 1. you must have either made a computational mistake or made some incorrect assumptions in analyzing statement 1..
Tim Sanders
Manhattan GMAT Instructor

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erin.m.mcelroy
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Re: Are X and Y both positive?

by erin.m.mcelroy Sun Apr 10, 2011 10:21 am

Can you please explain how you got to the final answer that they are both positive?
RonPurewal
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Re: Are X and Y both positive?

by RonPurewal Wed Apr 13, 2011 5:22 am

if you were unable to find this question in a search, then you should start searching with quotes around your search strings. i.e., search
"are x and y both positive"
rather than just
are x and y both positive
(note the difference in the presence/absence of quotation marks)

the former of these search terms will only turn up threads in which these words appear in this exact order, and will thus instantly find the desired thread(s). the latter, of course, will probably find way too many things you don't want, since all of those words are extremely common individually.

--

here's an existing thread with 25 posts, on which your question is almost certainly answered already:
are-x-and-y-both-positive-1-2x-2y-1-2-x-y-1-t797.html

if your question is not already answered on that thread, please post ON THAT THREAD, not here.
thank you.