Since we do not not the level of difficulty of the questions during the test, what is the best strategy if we face difficult questions (take more than 2 minutes to answers, per se) ? My goal is just want to pass with at least 550 not 700.

1. randomly guess.
2. try to solve the problem
3. if i think it is too hard, i just guess as quickly as possible
4. or what......

Thanks

Definitely make an attempt at every question, rather than just looking at it and deciding it's not worth it. Several reasons:
1. Sometimes a problem will look harder than it turns out to be.
2. Doing the wrong math at first can sometimes remind you of the right math.
3. Doing some math, even not-quite-right math, can make your guess more educated.

(The exception: If you are so crunched for time you don't even have time to read the question, then randomly guess to avoid leaving blanks, which hurt you more than wrong answers.)

At about 1:45 into the question:

If you are not even on a path to the solution, then pull the plug and guess strategically. Use what you have completed to make an educated guess, relying as much as possible on the answer choices themselves.

If you are making progress, then go ahead and finish, but don't go over 2:30 on any problem.

_________________
Emily Sledge
Instructor
ManhattanGMAT

I agree with Emily except on one point: I'd make the decision about whether to guess at the 1min or 1m15s mark, not 1m45s.

Educated guessing takes time - you could easily spend 30-60 seconds figuring out ways to eliminate wrong answers. (And that's what educated guessing is: finding ways to identify, and eliminate, wrong answers even though you don't know how to do the problem the right way.)

I also completely agree that we shouldn't go over 2m30s on any problem. When you go over that timeframe, you are essentially guaranteeing yourself another question wrong elsewhere on the test (due to lack of time). There's no problem that's worth guaranteeing yourself another problem wrong, especially when your odds of getting this one right aren't that great (as evidenced by the fact that you've already spent 2m30s on it and you still don't have an answer...).

I also spend at least a minute on every math problem (unless I'm so far behind that I have to make a random guess immediately in order to get back on track). If I can do a problem in 30 sec, I do it again, just to make sure I didn't make a mistake and overlook something. :)

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT