Firstly, I think CodeGym provides a great course to learn Java. One of it's stated objectives is to provide many practice problems, as human beings learn through repetition. Pursuant to this goal,however, previously answered questions should be made available for solving. I know that once I finish the course, certain lessons will be forgotten and it would be nice to work on practice problems in those sections at a later date, to "freshen up". Please consider updating the site to provide this capability, as it would enrich the learning experience!