*Mathematische Rätsel für Anfänger und Fortgeschrittene*

**Author**: Ernest Dudeney

**Publisher:** BoD – Books on Demand

**ISBN:**

**Category:** Mathematics

**Page:** 156

**View:** 349

Der Engländer Dudeney hat zwar nie Mathematik studiert, gilt aber heute als eines der mathematischen Genies seiner Zeit. Das hier neu bearbeitete Werk aus dem Jahr 1917 schaffte es denn auch in die zeitgenössischen Bestsellerlisten und ist auch heute noch ausgesprochen populär. Es verbindet in einzigartiger Weise Spaß mit Mathematik und darf daher als einer der großen Klassiker des poulären Sachbuchs gelten.

430 PUZZLES, PROBLEMS, PARADOXES, AND BRAIN TEASERS.

Intriguing math teasers for ages 11 up, brilliantly answered. - This excellent collection of teasers has inferential problems in arithmetic and algebra, and includes geometry, mazes, magic squares and a lot of chess-board tours. The answers are often gems in themselves -- things mentioned in passing and left to the reader to establish -- e.g. ... of the twelve ways that eight queens can be placed on a chessboard without attacking one another... At twelve years old I spent many an hour finding those twelve ways. I still find challenges in it in spite of my Masters degree in Mathematical Physics! With 430 puzzles, problems, paradoxes, and brain teasers, this book is a mammoth puzzle collection, compared with most math teasers and puzzles book available. But what is important is not the quantity, but the quality and charm of the problems presented. Each problem is presented with a full length solutions that makes the book absolutely an instructive experience for the reader. In some cases the author even discussed on how others had attacked and failed the problems. You, your freinds and family will spend many hours trying the vast array of puzzles prented in this book.

Amusements in Mathematics: Large Printauthor: Henry Ernest Dudeney'Twas last Bank Holiday, so I've been told, Some cyclists rode abroad in glorious weather. Resting at noon within a tavern old, They all agreed to have a feast together. "Put it all in one bill, mine host," they said, "For every man an equal share will pay." The bill was promptly on the table laid, And four pounds was the reckoning that day. But, sad to state, when they prepared to square, 'Twas found that two had sneaked outside and fled. So, for two shillings more than his due share Each honest man who had remained was bled. They settled later with those rogues, no doubt.

In issuing this volume of my Mathematical Puzzles, of which some have appeared in periodicals and others are given here for the first time, I must acknowledge the encouragement that I have received from many unknown correspondents, at home and abroad, who have expressed a desire to have the problems in a collected form, with some of the solutions given at greater length than is possible in magazines and newspapers. Though I have included a few old puzzles that have interested the world for generations, where I felt that there was something new to be said about them, the problems are in the main original. It is true that some of these have become widely known through the press, and it is possible that the reader may be glad to know their source. On the question of Mathematical Puzzles in general there is, perhaps, little more to be said than I have written elsewhere. The history of the subject entails nothing short of the actual story of the beginnings and development of exact thinking in man. The historian must start from the time when man first succeeded in counting his ten fingers and in dividing an apple into two approximately equal parts. Every puzzle that is worthy of consideration can be referred to mathematics and logic. Every man, woman, and child who tries to "reason out" the answer to the simplest puzzle is working, though not of necessity consciously, on mathematical lines. Even those puzzles that we have no way of attacking except by haphazard attempts can be brought under a method of what has been called "glorified trial"-a system of shortening our labours by avoiding or eliminating what our reason tells us is useless. It is, in fact, not easy to say sometimes where the "empirical" begins and where it ends. When a man says, "I have never solved a puzzle in my life," it is difficult to know exactly what he means, for every intelligent individual is doing it every day. The unfortunate inmates of our lunatic asylums are sent there expressly because they cannot solve puzzles-because they have lost their powers of reason. If there were no puzzles to solve, there would be no questions to ask; and if there were no questions to be asked, what a world it would be! We should all be equally omniscient, and conversation would be useless and idle. It is possible that some few exceedingly sober-minded mathematicians, who are impatient of any terminology in their favourite science but the academic, and who object to the elusive x and y appearing under any other names, will have wished that various problems had been presented in a less popular dress and introduced with a less flippant phraseology. I can only refer them to the first word of my title and remind them that we are primarily out to be amused-not, it is true, without some hope of picking up morsels of knowledge by the way. If the manner is light, I can only say, in the words of Touchstone, that it is "an ill-favoured thing, sir, but my own; a poor humour of mine, sir." As for the question of difficulty, some of the puzzles, especially in the Arithmetical and Algebraical category, are quite easy. Yet some of those examples that look the simplest should not be passed over without a little consideration, for now and again it will be found that there is some more or less subtle pitfall or trap into which the reader may be apt to fall. It is good exercise to cultivate the habit of being very wary over the exact wording of a puzzle. It teaches exactitude and caution. But some of the problems are very hard nuts indeed, and not unworthy of the attention of the advanced mathematician. Readers will doubtless select according to their individual tastes. In many cases only the mere answers are given. This leaves the beginner something to do on his own behalf in working out the method of solution, and saves space that would be wasted from the point of view of the advanced student. On the other hand, in particular cases where it seemed likely to interest...

For people of all ages who enjoy puzzles with a mathematical flavour.