We had test banks. They were tests that profs had handed back. The profs knew that these tests might “make the rounds” for future students to study from - whether that was within Greek systems or just among friends (“hey, I know you’re taking Econ 201 next quarter, I’ll save my notes and tests for you”). I don’t see the issue, personally. We were still STUDYING from these tests. Cheating would be breaking into a system and getting a test that hadn’t yet been administered or that the prof didn’t hand back.