One Hundred 100 Games of Logic by Pierre Berloquin - Paperback

Not too easy and not too difficult, the puzzles in this book are great fun to work on.

The puzzles in 100 Games of Logic have been selected and designed so that they will not be too difficult to solve for the average reader who is not a mathematician, and at the same time not be too easy.  They are all clearly present, accurately answered at the back of the book, and great fun to work on whether you crack them or not.