How much do you really need to "study" in college?

I guess it all depends on the courses that you take. But, it’s also interesting that some people study at differently from others and that everyone has their own strategy…

What’s your question actually?

As much as it takes.

Nominal time commitment for a full time student on track to graduate in 8 semesters of 12 quarters (15-16 credit hours per term) would be 45-48 hours per week, including both in-class and out-of-class time.

Depends on the major, the school, the student, and what kind of grades you want. It is widely variable. One of my kids at a notoriously rigorous school did very little outside of academics, eating, and sleeping her first year, just to pass her classes. The other, at a less rigorous school and in a less rigorous major, worked hard (all As, Phi Beta Kappa), but still had plenty of time for clubs and fun with friends.

“Study” not so much.
Study, at least some time per day.

2-3 hours per hour in class, generally. Obviously it depends on the classes and the college.

It all depends…but
The government/accreditation assumes that for every academic hour in class, you need to do 2-3 hours of studying/reading/homework.