Not to get too off topic, but where I went to school, 'bibles' are accepted and expected by students and faculty in both dorms and greek system. These bibles had class notes, homework assignments with solutions and exams with solutions. One of the best ways to learn material is through additional problems and self exam. To make things fair, most professors would hand out copies of previous years exams with their solutions for students that didn't have access to a course 'bible'. In fact, they even made a website which is essentially a big 'bible' of every course in the school (
http://ocw.mit.edu/index.htm). I still have all the 'bibles' from the classes I took and when I was in school I would let other students borrow them when they were needed. Bibles are often better resources then text books when I have to review something I learned in school.
What do professors expect happens when you pass back student exams? That no one will look at them again. Any course that I teach, I make new homework and exams each and every year. To do otherwise is lazy and asking for it.
As for your original question. I dated a sorority girl for 3+ years in college while I lived in a dorm and had no frat affiliation. I would say that each sorority and each sorority member is/are individual and caution against stereotyping them. They have their partiers, drunks, bookworms, goody girls, etc. The main difference I saw was a little less freedom traded for more organized and active social life.