Very nice observation! I have noticed this with my tutoring students. It is like adding insult to injury -- missing the question and taking extra time to do so...
Waiting until the two minute mark to see if you can solve may even be too generous. If you find throughout your practice tests that you are a person who usually uses all of your time on the quant section, then you may not want to invest 2 minutes on a question you are ultimately likely to have trouble getting right anyway. A better standard is that if within 1min 15 seconds you do not have a strategy picked out that you can execute on the problem then it is a good idea to make an educated guess.
Let me make just one more plug for my call for everyone to have a strategy to avoid misreading and calculation errors - in other words a way to not make the "silly" mistakes, such as answering for angle X when the question asked about angle Y. You see, if you find on test day that a question is outside of your knowledge and you do have to move on in 1min and 15 seconds and focus on the next question this is obviously not the desired result, but it is not a tragedy either.
A tragedy is when you know how to do a question, you execute it all the way to the finish and then you make a simple error in calculation, misreading, or -- let's say "detail" -- right at the end of the problem. Now you have missed the question just as surely as if you guessed at a problem that you could not do, but you have also taken an additional minute or more and you have devote some of your precious reserve of intense focus.
If there is one thing everyone needs to do it is have a strategy that helps you avoid making "simple" errors on test day. This is something that we emphasize throughout the quantitative lessons at Veritas Prep. Especially in the Data Sufficiency and Problem Solving lessons.
