Where are the Solutions for solve problems section? Like the explanation. Is it on the website ?
According to Greg, the current goal is to first get the number of problems to at least 200-300 and once he had a significant amount of problems in the question bank then the GregMat team will start with the process of integrating the solutions. Till then you can ask your queries on the forums!!
A very small minority have integrated video solutions, while many others have been covered in past POTD (problem of the day) or classes. Also searching on the forums can help.