2. Stamina : I took practice tests every 2 days before the real test.
The day before the test I did the GMAT Prep
And you know that this would likely LOWER your stamina, right? Taking a practice test the day before the real test is like running a practice marathon the day before the real marathon. You're not learning anything new. You're just tiring yourself out and you don't have enough time to recover fully before the real thing.
General timing should be:
Quant:
Q10: 55 min left
Q20: 35 min left
Q30: 15 min left
Verbal:
This is trickier because it partially depends upon where the 3 or 4 RC passages begin. The below assumes that one new passage starts within each quarter of the test (Q1-10, Q11-20, Q21-30, Q31-41).
Q10: 56 min left
Q20: 37 min left
Q30: 19 min left
You may have to adjust the above if the passages don't start in the way described above. For instance, if by the time you get to Q10, you've actually had 2 passages start, not just one, then you should expect to have fewer minutes left - maybe 53 instead of 56. If, on the other hand, you get to Q10 and you've had no passages start, then you should expect to have more - maybe 59 left. Every time a new passage starts, I keep track with a tick mark on the first page of my scrap paper. If you're worried about losing that or having to flip back to find the tick marks, then keep track on your hand - maybe with dots, so that you don't have as much skin to scrub later. :)
Remaining 5 minutes to the end of Quant sections, the proctor interrupted me , she asked how much time remain to the end of the section.
That is very annoying and you should file a complaint. They may not do anything but, hey, maybe they'll let you take the test for free next time!
It sounds like you had a timing problem, if you had 4 questions to go with 5 minutes left in quant. That also could have brought your score down, perhaps significantly. If you got all 4 wrong in a row, for example, that could have dropped your score by 8 to 12 percentile points (that's just an estimate - there are a LOT of variables that go into that calculation).
Percentiles do show your performance relative to the other pool of test takers, but this performance is normalized over a period of years (remember that scores are valid for 5 years, so the data has to be comparable for all students whose scores are still valid). It's not completely unusual for people to get the same score (or even, unfortunately, a lower score). I think your focus now needs to be: why didn't I improve last time and what do I need to do in order to change the outcome next time?
When you take the test another time, the algorithm does not base anything on your prior performance. You have a clean slate - as far as the algorithm knows, this could be the very first time you're taking the test.
Okay, so back to the situation here. You obviously had a quant timing problem on the real test. What kinds of timing problems did you have on practice tests? (You can still have timing problems even if you finish the section on time.) Read this article, do the analysis described on a recent MGMAT practice test, and let me know what you found out:
http://www.beatthegmat.com/a/2009/09/23/evaluating-your-practice-testsThis article will also help you to identify the particular content areas that are giving you trouble.
If you find that you are mismanaging your time within a section (spending too long on some and then having to rush on others), then you need to learn about how long one minute is without looking at a watch or stopwatch. If you don't have one already, buy yourself a stopwatch with lap timing capability. When you go to do a set of problems, start the stopwatch but turn it over so you can't see the time. Every time you think one minute has gone by, push the lap button. When you're done, see how good you were - and whether you tend to over or underestimate. Get yourself to the point where you're within 15 seconds either way on a regular basis (that is, you can generally predict between 45 sec and 1min 15 sec). Note: at the same time that you are using the stopwatch to time this "1-minute" thing, also use the OG Stopwatch (in your student center) to track the total time spent on each question.
Now, how do you use that when doing problems? If you're not on track by one minute*, make an educated guess and move on. (The general idea is that if you're not on track by the halfway mark, you're unlikely to figure out what's holding you back AND have time to do the whole problem in the 1 min you have left.)
* For SC, 1min is well beyond the half-way mark (we're supposed to average about 1m15s here), but you can almost always eliminate at least some choices on SC in that timeframe. Once you've got that "I'm around the 1min mark and I'm struggling" feeling, go through any remaining choices ONCE more. Pick one. Move on.
The above also requires you to learn how to make educated guesses, which is something you can (and should) study on every single practice problem that you do.
This article, about how to analyze practice problems, may also be useful for you:
http://www.beatthegmat.com/a/2009/10/09/how-to-analyze-a-practice-problemAnd you may also want to try this article, about time management:
http://www.beatthegmat.com/mba/2009/12/22/critical-skill-development-time-management