Price reduced! This is a set of 7 subjects from Kato Seminar's Basic Problem Practice Course, known for its high-quality content. It has not been cut. I purchased it in 2023, but I'm selling it because I no longer need it. The covers show some wear, but there is no writing inside. The content is from 2023, so it's not that old and should still be perfectly usable. I think it's perfect for output after inputting knowledge. Personally, it was easier to understand than Agarooth's Important Questions! Please feel free to negotiate the price.