I think College exams are more difficult. I say this because  in high school you can wait until the last minute to study for the exam. In college you have to make sure and find a quit place to study. Professors are alot more strict then high school teachers, and they wont give you any re-takes. Professors wont tell you to take notes or what notes to take. They have one job and a time to do the job in, and they really could care less in you pay attention or not. This makes people independent in college, with really no assistance at all  therefore college exams are harder.