I love logic puzzles, particularly those that involve grids or tables in which you can figure out the answers by using more than one type of reasoning. Also, at age 68 I do at least one difficult puzzle every day to keep my mind challenged. There are a few puzzle books that you can purchase that are very good and start with some relatively easy puzzles and build up to ones that can take me half a day to figure out. There is one website that has these puzzles for free which I enjoy, but they're pretty easy, and all have the same structure. Thus, when I saw this puzzle book advertised at Amazon.com I was pretty excited to get it for my kindle. However, this type of puzzle book is not made for good translation into the kindle format. I was really disappointed. You would really have to copy everything over again to be able to attempt to solve the problems. Just looking at the confused puzzle structure was enough for me to not bother.