EMPOWERgmatRichC wrote:
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
hi empower ,
u are right that many times, there are redundant information...
But not in this case. Its very importantto read finer point between the lines..
it gives the speed as problems per minute.. now either a problem is solved or not solved, we cannot have a half solved problem..
this does mean that x and y are integers....
this is what i feel, although it may be possible the Q was not meant that way..
If you reread my post, you'll see that I made no reference to whether X and Y were integers or not (that point is irrelevant), only that X/Y had to be 0 or positive. As such -(X/Y) will EITHER be 0 or a negative value, so -(X/Y) will ALWAYS be less than 3, regardless of the values.