Some observations have been made reagarding the GMAT scoring system. It is possible, even with 8-10 mistakes, to get 48-49 in Quantatative section. So don't be upset if you think you are scoring poorly. The test is adaptive, meaning each question is not weigh the same, but however you perform at the beginning of the exam will determine how the rest of the way is going to go for you. Second thing, if you get more question wrong toward the end of the test, it is still possible to maintain a high score. So just stay calm and concentrate.