I need an explanation on the 3 different types of relationships in the picture. And how can I solve these 3 problems?

Set up a relationship between STUDENT and COURSE: 1:M relationship where participation on the one side is mandatory and participation on the many side is optional STUDENTHO H COURSE is Enrolled N:M relationship where participation on one side is optional and participation on the other side is mandatory Is Enrolled ISTUDENTAL Of COURSE 1:1 relationship where participation on both sides is mandatory STUDENTI S Enolar ilot ICOURSE X