madhan_dc wrote:How rare are questions on GMAT with answer that cannot be determined?


I am in week 2 of preparations. I am still in book 1 kaplan math workbook, a little worried about the pace but i am making sure i am through with the content and error logs etc., I am always getting the answers wrong when there is a cannot be determined option and i choose that.

Is it pretty rare and does it mean i have to pay extra caution with those questions?

Yes, in a Problem Solving question, if there is a choice that reads "cannot be determined," it is rarely the answer -- furthermore, it is rarely if ever an actual choice on an actual GMAT question. It is much more common in the Kaplan materials than anywhere else. Don't worry about these too much. However, if you do see it, treat it as a Data Sufficiency concept: prove to your satisfaction that there are 2 possible answers, and if there are, then you can choose "It cannot be determined." Otherwise, always work towards the 1 answer on PS questions.

As Adam says it is very rare to find this in Official GMAT problem solving questions.

I think there are about two of these in the OG 12th and maybe one in the Quant Review. I would say one question in 100 has this option. Of course in Data Sufficiency it is always an option!

What I did notice is that because of the kind of questions that this question is offered on and because it is so rare you will want to keep it as an option. It seems to me that it was right more than 1/5 of the time that you would randomly expect. The answer to your question is that you should pay extra caution.