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 ...

Data Empire - Roopika Risam ****

The central thesis presented by Roopika Risam is that information gives us (and particularly countries) the power to organise, control and dominate others. Although I have a couple of issues with the presentation, this is a genuinely interesting trip through the history of our use of stored information from the earliest tallies to the latest information technology. I loved a quote from Lisa Gitelman that data is is always 'cooked' so 'raw data is an oxymoron'. This neatly underlines Risam's thesis that data and information are not neutral facts, but rather tools that (like everything from fire to electronics) can be used for good or evil. As we are taken through the historical context, it can sometimes be a little difficult to judge whether Risam regards a particular example as bad or good, even when the outcome is disastrous. One thing I didn't like too much is the adherence to a popular science writing approach that has got distinctly hackneyed: opening chapte...

Andrew Jaffe - Five way interview

Andrew Jaffe is professor of astrophysics and cosmology at Imperial College, London and director of the Imperial Centre for Inference and Cosmology. His new book is The Random Universe. Why science? I’ve always been interested in science, in particular in  astronomy, astrophysics, and space. One of my earliest memories - back in nursery school in New Jersey, I think - was watching one of the moon launches. I wanted that excitement to be part of my life! I never got to be an astronaut, but I did get to be part of the Planck Satellite team, and was privileged to be able to travel to the ESA Spaceport in French Guiana to watch the launch.  In between, I was lucky enough to have a supportive family, get a good education, and find inspiring teachers, mentors, and collaborators. They helped me model the universe, and helped me learn how to refine those models in the face of experimental and observational evidence. That is, they taught me to be a scientist. Why this book? The Random...