Received a PM asking me to respond.

How to study best will depend on your specific strengths and weaknesses. Are you struggling with content, technique, timing, or all of the above?

If content, what specifically is giving you the most trouble? (eg, in algebra, exponential equations; in word problems, rates)

On what types of questions or content areas are you struggling with technique or timing? (Technique is knowing how to identify / categorize a particular type of question and knowing what you're expected to do / answer as you move through the problem.)

Also give me any other detail you have noticed about your own strengths and weaknesses and the kinds of errors that you tend to make repeatedly.

If you need to do some analysis to figure out how to answer those questions, you can get good data from your practice tests. You don't mention what practice tests you're using, so I'll tell you how to use MGMAT practice tests to analyze. If you're using some other test, let me know (and if it's from a different test prep company, ask one of their experts how best to analyze the results from their test).

Run the MGMAT assessment reports and look for:
- areas on which you scored <50% correct
- areas on which you averaged >20sec above or >30 sec below what you were supposed to average
- areas on which there is >30sec (overall question categories) or >45sec (question subcategories) disparity in timing (in either direction) between the ones of that type that you got right and the ones that you got wrong

Also look at the individual question lists and review:
- problems on which you spent >30 sec above or >45sec below what you were supposed to on problems of that type
- problems below your level that you got wrong (eg, if you're currently scoring 650, look for problems in the 500-600 category)
Pat yourself on the back for things on which you scored >50% correct (the higher, the better) and for things you answered correctly in the general timeframe you were supposed to spend. For things you answered correctly very quickly, do still pat yourself on the back, but know that doing something too fast increases the chances you'll make a careless mistake - so just be careful.

Note on some of the timing data: if your timing got messed up in the section (eg, you spent too much time early on and had to rush later on), then your data will be skewed because you will have been forced to do questions towards the end much faster than you'd otherwise have done them (possibly to the point of making random guesses in a few seconds). If this happened in either section, you'll have to dive down into the data for individual problems rather than use the assessment reports to do the work for you, because the average timing may seem to be okay even though you had a bunch that were too long and a bunch that were too short.

See what you can decipher from that and come back and let us know where you're struggling the most (remember: not just percentage correct - also pay attention to timing and technique! If you get some particular type of question right all the time but always spend twice as long as you should, that area's a weakness, not a strength!).

Thanks for recommending our stuff, although I have to tell you guys that I tell my own students not to do the challenge problems unless they're already scoring in the 95+ percentile on quant - and sometimes not even then.

Basically, some of the problems are actually too hard - harder than what we'd really see on the test and be expected to do in 2 minutes - and, in some cases, what you'd have to study to do that problem is not actually helpful to you on the real GMAT. So take that into consideration.