This is a challenging book of puzzles; what I really liked about it was that after each puzzle there's a section that gives you some hints (or "solution schemes"), and then in the back of the book there are the solutions.

Sometimes I found that the "hints" really weren't really very helpful, and sometimes it would have been helpful if the solutions had gone into more detail and/or have been written more clearly. Sometimes they were hard to follow.

I can't believe I'm the first person to review this book after all these years. This book is one of the true classics in puzzle history. If you are a true lover of logic and thinking skills, then this is a must. I have spent the better part of 40 years collecting the best puzzles and this heads the list. Maybe the reason it has never been reviewed is that it is a demanding array of puzzles...not for the faint of heart.Thank you, Mr. Summers,for hours of pleasure.