Published in the UK in 2011

by Icon Books Ltd, Omnibus Business Centre,

39–41 North Road, London N7 9DP

email: info@iconbooks.co.uk

www.iconbooks.co.uk

This electronic edition published in the UK in 2011 by Icon Books Ltd

ISBN: 978-1-84831-349-1 (ePub format)

ISBN: 978-1-84831-350-7 (Adobe ebook format)

Printed edition (ISBN 978-1-84831-348-4) sold in the UK, Europe, South Africa and Asia by Faber & Faber Ltd, Bloomsbury House, 74–77 Great Russell Street, London WC1B 3DA or their agents

Printed edition distributed in the UK, Europe, South Africa and Asia by TBS Ltd, TBS Distribution Centre, Colchester Road, Frating Green, Colchester CO7 7DW

Printed edition published in Australia in 2011 by Allen & Unwin Pty Ltd,

PO Box 8500, 83 Alexander Street,

Crows Nest, NSW 2065

Printed edition distributed in Canada by Penguin Books Canada,

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Toronto, Ontario M4P 2YE

Text copyright © 2011 Johnny Ball

The author has asserted his moral rights.

No part of this book may be reproduced in any form, or by any means, without prior permission in writing from the publisher.

Typeset by Marie Doherty

Contents

Cover

Title Page

Copyright

Dedication

Foreword

How Ball of Confusion was born …

Introduction

1: Kitchen Capers and Domestic Problems

2: ‘I Can Hear You Thinking’ Puzzles

3: Any Number of Puzzles – About Numbers

4: Easy Peasy Puzzles and Catchy Watchy Questions

5: Geometric Shape and Angle Puzzles

6: Dear Old Faves from Days Gone By

7: Even More Thoughtful Thinking Puzzles

8: Party Puzzles and Tricks to Show Off With

Answers

Bibliography

For Four Grandchildren Woody, Ronnie, Nelly May and Albie

Just like your Grandad – life is always a bit of a puzzle!

Foreword

If I had a pound for every time someone had told me how my Dad’s television shows had made science and maths a joy for them when they were a kid, which in turn had encouraged them to follow a career in engineering or medicine or some other clever vocation … well then, I’d have a ridiculously enormous pot full of coins!

Exactly how many coins would be in that pot would take some figuring out – it might involve some guess work, perhaps some logical thinking. Of course you could just empty the pot and count the coins but that would be far too obvious. At this point my Dad would wade in and give a fantabulous explanation of averages and probability.

With my heritage you’d think I’d be good with numbers, a natural. Sadly this is not the case. The thirst for scientific knowledge and understanding of all things numerical is, apparently, not handed down in the genes. One might even argue that when it came to me the intelligence gene skipped a generation. I was an average maths student. I was only really good with digits when it involved remembering boys’ telephone numbers. ‘But you have the best teacher in the world right there in your Dad!’ people would say. Yes, occasionally I would ask for some help with my algebra homework and my Dad would ooze enthused explanations about the Egyptians’ weighing systems and Pythagoras’ theorem which, although fascinating, still didn’t explain to me why x² + y² = z².

It’s true, my Dad knows an awful lot about a huge number of things. What he doesn’t know about the history of science and mathematics is probably not worth knowing. His mind is like an Escher drawing; a never-ending maze of facts and figures about everything from Archimedes, Roman road building, gravity and trigonometry to Johannes Kepler, pi, space exploration, the universe … I could go on.

The best bit is that it’s all self-taught – he went to grammar school but never to university. He just read books – great books. He’s written a few good ones himself. He loves learning about how things work, how men and women have made such invaluable discoveries and how there is maths behind everything around us. Dad believes maths and sciences are terrific, important subjects and enormously fun to learn if taught with enthusiasm and energy.

Family gatherings in our house can be great fun – heated debates about who were better, the Egyptians or the Romans, arguments about global warming or over which is the most valuable number. The grandkids in the family quite rightly think Granddad knows everything – a taxi driver recently joked with me, ‘Most people have Google, your kids have Granddad.’

I’m so proud of my Dad and all that he’s done for the sciences and for education. He’s a very clever, brilliant chap, so it’s an absolute pleasure to share him with everyone. This especially includes the people who listen to my radio show, where we do a weekly feature called Ball of Confusion in which Dad sets puzzles. I, of course, rarely get them right but when I do it’s such a thrill – I even surprise myself. I do hope you and your family enjoy this collection of some of the best.

Zoe Ball

Summer 2011

How Ball of Confusion was born …

When my daughter Zoe began the BBC Radio 2 Saturday Morning Breakfast Show in 2008, her producer asked for ideas for special features. Zoe asked me if I could do a puzzle of some kind on each show. I would set the puzzle in the first hour and give the answer and explanation an hour or so later.

At first, I was worried that I wouldn’t be able to find enough puzzles that would work on radio, but I soon found that there was really no problem at all. Radio is such a wonderful medium, in that you can paint an image or set a scene in just a few words.

Zoe and I have now delivered well over 100 puzzles together and I am amazed to find that I am still nowhere near to running out of ideas. I have all my puzzle experience, which began at school, as well as my many old books on all things mathematical to thank for that.

I should mention that on the show, Zoe very seldom comes up with the answer to a puzzle. Now, that could be because she is really quite stupid at puzzles, but it isn’t that way at all.

When the show is transmitted the listener has an hour to deliberate and try to solve the problem before we give the answer. But for Zoe, there is no thinking time at all. For one thing, she has the rest of the show to do!

But more importantly, the puzzles are all pre-recorded. Otherwise I would be making a trip into the London studios every Saturday morning before dawn, for five minutes work. So about three times a year, we record a whole bunch of puzzles and for each, I deliver the question, and then almost instantly I launch into the answer and explanation. So Zoe really is allowed no thinking time at all.

She is actually quite good at puzzles – where she gets it from, I don’t know. Just like me, though, she is often slow to show confidence. However, given time and encouragement, she is pretty good at everything she sets her mind to. But I would say that wouldn’t I? I’m her Dad.

Hey, that’s an idea for my next book – ‘Ball of Compliments!’

Johnny Ball

Summer 2011

Introduction

When I was a comedian, it soon became apparent that there was no such thing as an original joke. Whatever the wise-crack, pun, witticism, tall tale, spoonerism, one-liner, play on words, rudeism or gag, it could always be proved to be a newer version of something that had been said before.

So it is with puzzles. If you want an early comic puzzle, try this! Why, in an Egyptian tomb did someone long ago inscribe the words (or rather hieroglyphs) that said, ‘Can I borrow your washing line? Someone’s spread jam on mine!’ It is clearly a joke, but the puzzle is who thought of it and chose to record it for posterity?

Almost all the puzzles in this book, though re-set or juggled about by me, were created by people in the past who revelled in puzzles. As with any good joke, there are always people wanting to pass puzzles on for others to enjoy.

Unlike most puzzle books, you will often find my solutions longer and more multi-faceted than the basic answer. This is because puzzles are to be understood, solved and learned from – that is, and always was, their purpose. To set a question and then, on a later page, give the answer as a single word or number would be of no use in helping a puzzled puzzler, who did not understand the question in the first place, to understand how that answer was arrived at.

So I have indulged myself and my love of puzzles by trying, in most cases, to extend the basic idea with mathematical thoughts that take the puzzler a step further and into a deeper realm of puzzle understanding. On occasion, as with the jug pouring puzzles, which I love, I will say, ‘If you liked that puzzle, then here are a few more in the same vein.’ Why? Because when a basic understanding dawns on a puzzler, they need to extend that understanding, to broaden their knowledge and appreciation of the variations on each particular theme. This is why people get hooked on Sudoku.

Sometimes I will credit the originator of a puzzle, because from my researches, I happen to know just who that person was. But on many occasions there will be no credit, even though I may have first encountered a puzzle in a book written by someone with a knowledge of puzzles far greater than my own. The reason I feel I can repeat the puzzle without giving them credit is that I am pretty certain they also found it written by someone who had gone before them.

In my modern day maths lectures I often open with a slide showing the Vitruvian Man, as drawn by Leonardo da Vinci. It shows a man set in a square with his arms outstretched, demonstrating that a man’s height is almost always the same as the distance his fingers can reach sideways. The Romans called both distances a man’s ‘stature’. The Vitruvian Man is also set in a circle, with a second set of arms reaching higher, to the very edge of that circle.

Have a look at the picture, then cover it and ask yourself, ‘What point is half way up the human body?’ Well? In my lectures, I invariably find that almost everyone will say, ‘Your waist, belly button or navel!’

But they are all totally wrong. Half way up your body is your pubic bone, at the point near the bottom of your torso, just above where your body starts to get interesting. The navel or belly button is about a span higher – the distance between little finger and thumb when a hand is outstretched.

Look at the Vitruvian Man and you will see that the navel is at the centre of the circle, not the square. This point is one span higher than half way up your body. If you reach either arm straight up above your head you will reach a point one cubit or two spans higher than your height. So the Vitruvian square is eight spans high by eight spans wide, but the circle has a radius of five spans and a diameter of ten.

But by far the most important thing about Leonardo’s Vitruvian Man is that from it we can understand exactly what learning is all about. Where did Leonardo, this man of a genius hardly even equalled in the past 2000 years, get the idea for the drawing? Simple – he nicked it from the architect Vitruvius, who designed the Roman Colosseum 1500 years before Leonardo was born. Sadly, the Colosseum itself eventually went broke – the lions ate all the prophets.

The tale of Leonardo and Vitruvius explains that all learning is theft. Almost all top sportsmen and women talk of the idols that inspired them when they were young. They learned to copy their idols until eventually