My calculated GPA was 4, and my high school marks were on the upper 80's-90's. I'm taking the 5 prep courses. It wasn't that hard for me as I had previous knowledge which helped me a lot, however I decided to take all the 5 courses to improve my english skills (english is my second language). I even managed to work part-time in the biginning of the semester. Now for people who had never seen the subjects before.. it's been tough. And don't forget you need to pass each one of them with at least 74% to advance to next semester.