It’s pretty difficult to graduate in 3 years from Brown. (I’m a Brown grad) Since there aren’t any requirements, APs are used more for placement into higher level courses not for credit. Also, 5 courses is the max you can take per semester but most people take 4. If you take 5 classes a semester, you graduate in 3 years since you need 30 credits to graduate (every course is worth 1 credit). You wouldn’t be able to study abroad though since the max credits you can transfer back is 4 from a study abroad program (I think), not sure that matters to you or not.