Hi, thank you for your reply.
Well, I've taken GMAT 3 times already with no big success. And many people say that the first questions will define what level of questions you will be asked, so it makes sense to do all that's possible to get those correct. Whatever happens afterwards is another story since if I dont get the first ones right I wont see the 600 questions anyways. If guessing to save time on the first questions pretty much guarantees you a 550 so what is the point to save time to get a low score anyways? Isn't it worth taking the risk to spend more time so at least you will be fighting for the high score?
Also, are you sure about the 90% thing?.. Isn't it more like if you get the 500s correct, you are a 600, if you get the 600s you are a 700 if you get the 700s you are a 800 (perfect score or close) ? This is my doubt actually. Getting 90% of 600s correct puts you on a VERY high level and a 47 is not high, it's somewhere in between, like not much above average.
Any thoughts?