
If the problem is summarized beforehand, and if your solution is clear, sensible and easy to read, you can easily study from it. If it is messy, not detailed, or illogical, it is not a useful studying tool. Even if it neat and logically presented, if you haven't summarized the question, studying from it becomes considerably more time-consuming.
Presenting your problem sets in such a fashion does take more time in the short run, but it is not a waste of time! It helps you internalize the material now, and makes studying for exams easier. The more you practice presenting your ideas in an organized fashion, the better prepared for life after college you are, no matter what field you choose!
Save each problem set once it has been returned to you! It can be an invaluable study tool.