Paul, SigEpUCI and Dookie do think that the challenges are representative. Remember that we try to mimic most of the challenges on a 49-50 Quant level,so unless you are doing very very well, you will not see many difficult questions on the real gmat. And getting difficult problems wrong does not cost you as much. Someone asked, well , how do we know its a difficult problem, which segways nicely into the whole concept of the challenges.
Our primary goal is to help you learn by letting you test your skills in a timed environment with a 'challenge'. Your focus should be on building strong concepts. The challenges, by forcing you to think harder, try to simulate the stress on test day and try to help you see your performance under a timed environment.

We take the word "Challenge" very seriously. We chose the word "Challenge" as we intend to strengthen your concepts and test preparedness by challenging your knowledge and your expertise with time management.

At this point, Your focus should be to use the knowledge you have gained from those challenges. Remember that test anxiety is the most common cause of lower scores. Go over the concepts that you are not very confident about.

- Dont panic at all if you cant solve a problem. Try to let go of a problem if you cannot absolutely solve it . Narrow down the choices, pick your bes t guess and move on. Key is not to get bogged down.

- Do not judge how you are doing. let the test do the scoring, dont think about your score. One question at a time. remind yourself this after every question

- Ofcourse, Sleep well the night before the test.

After your test is done, please take some time to give us some feedback.

Thanks christoph
Praetorian