These are schools I'm not speaking in regards to any specific schools, but rather to the general principle. In my experience, many students (myself included) h

These are schools I'm not speaking in regards to any specific schools, but rather to the general principle. In my experience, many students (myself included) had plenty of obstacles to attending "office hours" - jobs, other classes, volunteer activities, etc. I won't dispute that there are some circumstances where some students can (and do) take advantage of this, but it doesn't seem to me that - broadly speaking - "office hours" are particularly effective strategy for most people. If that is the case then how likely is it that it would have been helpful if the instructor had provided a written solution with the problem in the first place? Good question. I suppose it depends in part on whether the instructor themselves made up the problem & solution, or it it came from a 3rd party. In either case, at least if you have a written solution you tighten up the cycle time to finding out that your understanding is flawed, which opens up more opportunity to pursue alternate explanations - maybe an online forum, a private tutor, or just consulting a different book, etc.