Two fathers and two sons leave town. This reduces the population of the
town by three. True? Yes, if the trio consists of a father, son, and
grandson. This entertaining collection consists of more than 200 such
riddles, drawn from every branch of mathematics. Math enthusiasts of all
ages will enjoy sharpening their wits with riddles rooted in areas from
arithmetic to calculus, covering a wide range of subjects that includes
geometry, trigonometry, algebra, concepts of the infinite, probability,
and logic. But only an elementary knowledge of mathematics is needed to
find amusement in this imaginative collection, which features complete
solutions and more than 100 black-and-white illustrations.
"Mr. Northrop writes well and simply. Every so often he will illuminate
his discussion with an amusing example. While reading a discussion of
topology, the reviewer learned how to remove his vest from beneath his
jacket. It works every time." -- The New York Times