Okay, multiple choice questions. I've done this in multiple exams and the chance of guessing it right is ~60% in my own experience. Please remember I'm in Melbourne and I'm doing it the "Melbournian" way. I think like this: If I'm an examiner, would I put my answer @ A? No, that's pretty dumb right? Anyway, that's just a starter.
Next, well I found this way after analysing exam questions here in Victoria and I got almost every multiple question right in a music theory exam (90%) as well as a math exam (60% correct guessing). Well, I'll admit. I took a couple of different test papers and tried to guess the whole thing although I know what to do. I figured that if I got stuck, there must be some kind of pattern in the examiner's brain. Look for mutual things!!
A: 11425 666 89
B: 12435 667 87
C: 11425 666 87
D: 12535 667 87
Guess which one is the correct one? It's C - most mutual "stuff". Of course this method doesn't always work, but it's a great method. I'm not a great explainer but I hope you get what I'm trying to say here. Hope this helps.
But hey, stop guessing, get a pen and start studying more. There's nothing worse than guessing your way through an exam. The things I fail during my high school years is a lack of planning and studying.