Sudoku Hard is for those who love the hard puzzles with 300 large print two puzzles a page, they are large enough to write your notes in the squares and around the outside of the puzzles.Instead of having all the answers at the end, I have made it easier for you and arranged the book into three sets of 100 with answers after each set.This book is 8.5 x 11 inches with 230 pages and there is no introduction at the start explaining the rules and solving techniques which I am sure you do not need.