i just finished my 5th MGMAT CAT with 4 days to go!!! in the math section i noticed there were at least 10-15 questions towards the end of the section which I got right...however they were all 600-700.. shouldnt the algorithm start giving me some 700-800 level questions after getting several 600-700 questions. that seemed to be the case for tests 1-4...just wondering how the algorithm is set up.

If you have been scoring very highly on the quant, you may have started to exhaust certain portions of the pool of test questions. Eg, the test is required to give you a certain number of, say, geometry questions. If you have been scoring so highly that you've mostly been answering 700-800 questions in your first four tests, by the fifth test, there might not be enough 700-800 level geometry questions to give you. The requirement for the content area will override the requirement for the difficulty level - so, in this circumstance, you'd be given a 600-700 geometry question rather than a 700-800 level question from another content area.

Also - this is probably too late for you since it sounds like you took your test today, but for others: don't take practice tests within 3 days of the real thing and, ideally, don't take tests within about 5-7 days of the real thing. You risk tiring yourself out right before d-day.