Puzzles for Pleasure

This is not a book for passing the time on the train! Some of these problems are real tough nuts to crack. This guy must have one hell of an IQ 'cos I got a first in maths and some beat me. It's not that the maths needed is difficult, it isn't (grammar school algebra at most). It's just that the way of looking at them requires a particularly visual mind. I'm thinking mainly about the Advanced Puzzles some of which were beyond me (unt...