Skip to main content

The Price of Cake: Clément and Guillaume Deslandes ***

This is a bit of an oddity that is likely to prove Marmite-like in attracting a mix of enthusiasm and dislike - so three stars is something of an average outcome. The authors describe it as 'a compendium of difficult mathematical riddles'. I don't think this is strictly accurate: these aren't riddles in any conventional sense, they are word-based mathematical problems or puzzles, but lack the wordplay that is essential to a riddle.

Which side of the divide you come down on is likely to depend on two factors. Whether you like indulging in mathematical problems, and whether you only like mathematical problems where an intuitive grasp is enough, or whether you enjoy ploughing through mathematical workings to get to the solution. I suspect my use of the word 'ploughing' there highlights that, while I personally do like them, I haven't the patience for problems that take a lot of working through.

For those of us with limited patience, there is a hints section that gives something of a pointer to the way of approaching the problem, before a detailed solutions section (the longest part of the book). It's probably best to give an example. The first 'riddle' says that a blacksmith has five chains, each with three links. He wants to make a chain 15 links long. Given he can open and close links, what is the minimum number he needs to open. The hint tells us that four links is obvious, but is it optimal? And the solution gives the actual answer.

Here the  answer is practically one line: this is the kind of intuitive puzzle I find appealing. But with a fair number there was some mathematical working required. The subtitle mentions these are 'classic' riddles - and almost every popular mathematical problem I've come across is in there, from Monty Hall to the seven bridges of Koenigsberg, via plenty of statistical and speed of travel problems, both familiar and novel.

In practice, I did enjoy it rather more than I thought I would, though for me it would have worked better if the solutions had come straight after the relevant problems - I spent most of my time reading a problem, failing to solve it then flipping to the back to read the solution.

Not at all a bad book (though I wish the cover had looked a little less self-published) - but one with a very specific readership. You'll know if it's for you - and if it is, you should get a copy.

Paperback:   
Kindle:  
Using these links earns us commission at no cost to you
Review by Brian Clegg - See all Brian's online articles or subscribe to a weekly email free here

Comments

Popular posts from this blog

Mathematics with Love – Mary Stopes-Roe *****

Admittedly it’s early days (this review is written in January), but this, for me, is the surprise hit of the year so far! I approached this book with trepidation, but found it absolutely delightful. It is described on the cover as the “courtship correspondence of Barnes Wallis, inventor of the bouncing bomb”, and contains a series of letters between Wallis and his cousin and eventual wife Molly Bloxham, along with some useful annotation by their daughter, Mary. The courtship itself is not without difficulties, as Wallis was 18 years older than the 17-year-old Molly at the start of the correspondence, and her father, not surprisingly, wasn’t too pleased about the interest of such an elderly suitor, but that isn’t the only reason the letters are interesting – it’s also because of maths, and Wallis’s position in the UK as the engineering hero of the Second World War. (Incidentally, it seemed very strange to see letters addressed to “Barnes” – I had always assumed Barnes Wallis was a ...

Why Nobody Understands Quantum Physics - Frank Verstraete and Céline Broeckaert **

It's with a heavy heart that I have to say that I could not get on with this book. The structure is all over the place, while the content veers from childish remarks to unexplained jargon. Frank Versraete is a highly regarded physicist and knows what he’s talking about - but unfortunately, physics professors are not always the best people to explain physics to a general audience and, possibly contributed to by this being a translation, I thought this book simply doesn’t work. A small issue is that there are few historical inaccuracies, but that’s often the case when scientists write history of science, and that’s not the main part of the book so I would have overlooked it. As an example, we are told that Newton's apple story originated with Voltaire. Yet Newton himself mentioned the apple story to William Stukeley in 1726. He may have made it up - but he certainly originated it, not Voltaire. We are also told that ‘Galileo discovered the counterintuitive law behind a swinging o...

On Time - Jim Al-Khalili *****

By a small margin Jim Al-Khalili's The World According to Physics is my favourite of his books, both because the 'three pillars' concept at its heart works so well - but also because it's short. On Time is somewhat heavier, but thankfully not a wrist-buster. It might seem at first sight odd that a book on a subset of physics is considerably longer than one covering the whole thing, but time is one of those subjects that inevitably involves considerable complexities and needs depth. As Al-Khalili establishes, it's hard to think of any other scientific concept where our perception of it - what he refers to as manifest time or psychological time - is so different from the view from physics. Some physicists go so far as to suggest that time doesn't exist at all. In the book, Al-Khalili sets out (to my mind quite successfully) both to explain why they think this is the case, but also why it's not the best interpretation of time. I'd certainly note that I...