As expected from this author, the topics are well chosen and the counter-intuitive results intriguing.
However,contrary to my experience with Havil's earlier books, "Impossible" seems to reflect hasty preparation and/or careless editing, hence the lower rating. An earlier review referred to the error in the proof of the irrationality of log2. To this can be added a number of others. For example: wrong signs in the Taylor expansions of sinx and cosx (p.226);numerous P(n-k,k)instead of P(n-k-1)in the coin toss discussion (p.97); log n - 2/3 instead of log n -3/2 (p.101);over-counting by a factor 3! in the mathematical expression for the number of ways of picking one pair(not two pairs as stated)in a poker hand, and the omission of -40 and -1098240 in the last line of the odd card discussion (p.106). While It should be emphasized that this is not a book for the casual reader,even the reader with some measure of mathematical sophistication will be frustrated by such errors and misprints;certainly, an unnecessary impediment to what could be a enjoyable journey for one seriously interested in mathematical conundrums.