Dear GMAT Club community
During my GMAT preparation, I noticed that I often struggle with Data Sufficiency questions. The reason that I struggle is because of questions like the following:
Question stem: "Is X greater/better than Y? Subsequently I often find out that, with the information given in the two statements, it is possible to calculate the difference between X and Y. However, after making the calculations, I often find out that X is NOT greater than Y. This puts me in an insecure position, because I doubt whether I should answer that the information given is sufficient (answers A, B, C, or D), or that I should answer that the information given is insufficient (answer E). After all, the answer to the original question is the following: "No, X is NOT greater than Y". So I'm inclined to pick answer E (NOT sufficient).
Can somebody tell me which rule I should apply in these type of situations?