Rick can solve x algebra problems per minute. Matt can solve y calculu

Hi All,

Certain DS questions on the Official GMAT will include a "redundant" piece of information in one (or both) of the two Facts. By 'redundant', I mean that it is information that was either already given in the prompt (or something that you can deduce from the information in the prompt). Redundant Facts are always insufficient (since you already had the information, the Fact does not offer anything new).

Here, we're told that Rick can solve X problems per minute and Matt can solve Y problems per minute. Neither of these 2 variables can be negative (a person cannot solve "negative" problems in the context of this question). We're also told that Y CANNOT be 0. As such, X/Y is either 0 or it's positive, so the information that -(X/Y) < 3 is redundant, since -(X/Y) is either 0 or it's negative and ALL of those possibilities are LESS than +3. Thus, Fact 2 is INSUFFICIENT.

While redundant information isn't that common on the Official GMAT, you'll likely have to deal with it at least once, so it's important to take the proper notes and make whatever deductions you can with the information that appears in the prompt.

GMAT assassins aren't born, they're made,
Rich