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basic question about PS [#permalink]
20 Dec 2006, 21:10
0% (00:00) correct
0% (00:00) wrong based on 0 sessions
I'm a quick question; hope you can clear it up.
I have a problem that says X and Y are integers > 0. If it's not specified that X != Y, can X = Y? I have an old DS pdf where I got a problem wrong because of this. A solution was possible where X = Y, but the official answer supposed they were unique.
I found that the OG doesn't mention whether the 2 variables can be equal, but my answers match up if I assume that X can be equal to Y.
In high school and college, when we used 2 variables X and Y, the presumption was that they were different.
in general, don't assume anything that is not specifically given.
there are very few exceptions to this.
GMAT questions (and OG) are very accurate. (other prep material, from my experience, is much less accurate and contains some errors and underlying assumptions).
this is is especially true to the question you asked. if there are two distinct variables, they can be equal unless you are specifically told otherwise (or it can be inferred otherwise from other data given)