780 is unbelievably
high. There's really not one specific way that I can tell you "oh, do this, and you can get to 780." By definition, the vast majority of test-takers don't get there - even 99th percentile test-takers! As you've already learned, you can't even set a date or time limit on this kind of goal. It takes whatever time it takes and that's that.
Why do you want a 780? I'm not exaggerating when I say that literally the only reason you would need a score THAT high would to teach for us. :) (And even we only require a 760 or higher.)
First, read this:http://www.manhattangmat.com/articles/7 ... erence.cfm
As you'll see from that article, this is not a matter of "studying enough" or "doing a ton of problems." It's about developing a particular mindset, a particular ability to recognize patterns, and a particular ability to think flexibly and lightning-fast. Those skills help, to some extent, for any scoring level, but those skills are absolutely required if you're going to hit 780.
Take a look at the "how to learn" section of this article (it's in the second half):http://www.manhattangmat.com/blog/index ... an-part-1/
And also this article:http://www.manhattangmat.com/articles/a ... roblem.cfm
Do you analyze those kinds of things when studying? To get to a 780 level, you have to be at the point where you could practically right these questions yourself. You could explain to another expert how the question was constructed and why it was constructed in the way that it was. And, of course, you could teach questions to lower-level students - not just tell
them how to do something, but actually teach
Okay, I'm not trying to scare you away from this goal, I promise. I just want to make sure you know what you're getting yourself into. I talk to a lot of people who think scoring in the 99th percentile is just a matter of studying "enough" and that's really not how it works.
I also want to make sure that you've got a very good reason for going for a 780. The amount of time and energy this is going to take is huge - so you only want to do it if you have a really good reason to need that kind of score.
If you want more specific advice, use the below to analyze your most recent MGMAT CAT(s):http://www.manhattangmat.com/blog/index ... ice-tests/
Then come back here and tell us the results of your analysis and what you think you should do based on that analysis. (Note: do share an analysis with us, not just the raw data. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)
You do mention timing as an issue, so read these two articles and start doing what they say. (And, yes, the advice applies even for 780-level scores, with the sole exception that you will be getting a higher percentage of questions right than described in the article - but you will still miss questions, even at that level.)http://www.manhattangmat.com/blog/index ... to-win-it/http://www.manhattangmat.com/blog/index ... nt-part-1/