[laurentl]

For what it’s worth, I find that the answers to the problems in tAoCP are almost always a good balance between explaining the steps to get to the solution and leaving enough out that the reader still has to work to understand how the proof works. But that’s not applicable to all types of exercices.

Your proposed solution (include solutions for a few problems) is definitely a good approach: enough to help the self-learners along while forcing the students to work—I assume you’ll be assigning the unsolved problems in class :)