My Best Puzzles in Mathematics

From the Preface:

There is little that I need say by way of introduction to this collection of puzzles. They are all strictly "mathematical," though the mathematical knowledge necessary for solving them is, in all but a handful of cases, elementary. That is because these puzzles have all been published serially in various newspapers and magazines, and their appeal would be negligible if their solution demanded advanced mathematics.
They appear here, with their original wording unchanged, except that, where puzzles involve monetary calculations, I have converted pounds, shillings, and pennies into dollars and cents. The factual basis of many of these puzzles is derived from various games, e.g., contract bridge. A good many are based on Britain's national game: association football ("soccer"). You don't need to know this game to tackle the puzzles based on it. Its scoring is simplicity itself: each side, if it scores at all, merely scores one, two, or more goals.