Puzzling

Press, Volume CIV, Issue 30919, 27 November 1965, Page 4

Puzzling

Puzzle* and Paradoxes. By T. H. O’Beirne. Oxford Uni-

versity Press. 238 p.p.

This is good value for money for those who dare expose themselves to the conrtant temptation which arises from having unsolved puzzles in the house. The book is erudite and explicit and far better than a plain collection of mathematical teasers, for it tells us about the variants on old problems, the mathematical side issues which they raise and, where they are members of a general class, the properties of that class. All the forms of the problem of finding the false coin in a group by weighing them will be found, and the author's explanation of why some solutions do not work is valuable. The author is chief mathematician of a precision engineering company but the formal mathematics are slight, and any reader who can think logically for at least some of the time will enjoy this: it would be a suitable Christmas pi esent for an undergraduate

niece or nephew. To give the reader a foretaste of the quality of the book, here is a problem set by the Sth century scholar Alcuin: “Three jealous husbands with their wives have to cross a river in a boat which only holds two. How can they cross so that no woman shall be left with any of the men unless her husband is one of those men?"