This is a problem book for efficiently learning probability and combinatorics. There is a torn part, which is shown in the third image. There is also some writing, but it should be fine for overcoming weaknesses and practice. Negotiations for price reduction are welcome. Please feel free to contact me. You can get a discount when purchasing with other items! - Title: Mastering Combinatorics and Probability in 10 Days - Publisher: Kyoken Shuppan - Price: 790 yen (excluding tax) - Contents: Problem book on probability Thank you for looking.