GMAT Strategy

Agree with mayonnai5e. A couple of other points.

It's okay to go to, say 2.5 minutes, because sometimes you'll do other questions in 1.5 minutes. It's not so great to go to 3+ minutes because now you're talking about doing some other problem in under 1 minute, and that's not going to happen very often, unless you are at the super-high end of the scale.

Whether you are doing single problems timed or a set of problems, generally hold yourself to the time limit the first time through. Pretend it's the real test - you need to get SOME answer, somehow, in the given timeframe. Afterwards, feel free to spend all the time you want doing the problem again, going back over and analyzing it, etc. But the first time - figure out how you're going to get yourself to some answer within the given timeframe, because that's what you're going to have to do during the test.

One of the things you should think about afterwards, by the way, is: did I spend my time in the best possible way here? Is there some other way I should have thought about this or approached this? Now that I've done the problem once, can I see some better way to do it? (This happens a LOT if you just take the time to think about it.) And now that I've figured out a better way to do a problem of this type, how am I going to remember, and how am I going to recognize a future different problem of this same type, so I know I can use the same solving method?

All very important things that you just don't have time to think about during that initial 2 minutes you spend doing the problem for the first time...