This is a book of 'puzzles, problems and perplexing posers' - just the thing for a Friday. They vary from classic 'if two cats could kill three mice in...' type problems, through logic problems to tricky little numbers that rely on very careful reading of the question.
Inevitably, if you've been about a bit like me, you will have come across a few of them before. And there are bound to be some you just can't be bothered with. But as long as you get any enjoyment out of these types of brain teasers you are bound to find something that is truly entertaining. And, of course, Johnny Ball presents them with his characteristic charm. Just occasionally I found his 'funny' intros to the problems better suited to a ten-year-old's taste than mine, but mostly they are fun and keep the book from being literally a list of puzzles.
The only criticism I have is that when you are setting puzzles, some of which involve trickery and misleading wording, you have to be absolutely spot on with the wording of your challenge, or it can be legitimately cheated. Here's an example where Johnny got it wrong:
Find a fluted glass and a large and a small coin; say a 5p and a 10p. Place both coins in the glass, so the larger coin lies flat and over the small coin. Your impossible task: can you get the small coin out, without touching either coin.The solution given is relatively complex and not something you may think of (and it wouldn't work with the kind of flutes I have). But the book misses the obvious one. Pick up the glass and tip the coins out. You have got the smaller coin out without touching either coin. There's nothing in the problem statement that says that the larger coin has to stay in the glass.
This is a rarity, though, and many of the mental challenges and puzzles (mostly they don't involve something physical like this) are genuinely entertaining. If you have friends and relations who enjoy a bit of head-scratching fun, this is the present for them. See at Amazon.co.uk and Amazon.com - also on Kindle at Amazon.co.uk and Amazon.com.