I noticed that on one of the practice tests, it was mentioned that there were three forms, A, B, and C. For one form, a raw score of 75 would've gotten you a 900. On another form, a raw score of 60 would've gotten you a 900. Is it true that different forms can be harder than others, and the fact that they have different forms with (I am assuming) different questions is a way to trip you up when you're taking the test so that you can't estimate how many questions you can guess on or not do and still get a certain score?
1. No calculators on the PGRE and the general GRE?
2. Must everything be taken on a computer? I would rather take a paper version.