So if you get the answer right, it gets harder. Wrong, it gets easier. So the questions might get harder and harder until it finds your point and then you might get like one wrong, then the next right, and the next wrong, and etc...So that it is 95% sure you will pass.I remember someone saying "the more you answer correctly, the more harder it gets" And vice versa.
So a lot of people leave the test and get nearly half of the questions wrong, but still pass. There is a whole video out there explaining it with graphs and such.