A college class lasts about 45 minutes, 160 is 7200 minutes, and 120 is one hour and 60 minutes. Basically, a college class lasts 40-45 minutes, and 160 is almost the same.
University teachers are filing class hours and compiling class materials. College students also sign in according to class hours to get credits, and the teacher will check the number of classes at the end of the period.