I believe they meant three hours per week for each hour of class. So if you have 6 courses, each with three hours of lecture a week, you'd spend 3x3x6=54 hours a week. That's still pretty rough but that's what happens if you need to study hard for 6 classes.
That would put me at 18hrs of studying a day :/
Due to years of posting nonsense online, English is easy for me (top of the class). Not looking forward to my 2 science requirements though as thats where I struggle to concentrate.