Where did the Rubik’s Cube come from? How did it become so popular? And just how many possible combinations are there? Broadcast on BBC Radio Cambridgeshire.

# Tom Rocks Maths S02 E02

The second episode of season 2 of Tom Rocks Maths on Oxide Radio – Oxford University’s student radio station. Featuring the numbers behind the sub 2-hour marathon world record attempt, P versus NP and the battle for control of the world, and the usual dose of Funbers with my super sweet 16. Plus, music from Blink 182, Billy Talent and Hollywood Undead. This is maths, but not as you know it…

# Christmas Stamps

This Christmas themed puzzle was featured on BBC Radio 4’s Today programme as the 375th ‘Puzzle for Today‘. You can listen to the broadcast here at 48:55.

Christmas stamps are sold with the following values 16p, 17p, 23p, 24p, 39p and 40p. You want to send a present which has a postage cost of £1.00. How many stamps do you need to buy to make the exact amount?

Send your answers to @tomrocksmaths on Facebook, Twitter, Instagram, YouTube, or using the contact form on my website. The solution will be posted with the next puzzle.

Merry Christmas!

# SJC Inspire: how to design a successful video game

Very excited to announce the launch of the SJC Inspire digital magazine this week – a project I’ve been working on for the past few months in my role as Access and Outreach Associate for STEM at St John’s College, Oxford.

The first issues is ‘how to design a successful video game’ and features articles by researchers at St John’s, video interviews with students at the college, and practice puzzles set (and solved) by real Oxford tutors (myself included). I’ve highlighted some of my favourites below, but be sure to check out the full contents of the issue on the website here.

My former tutorial partner, James Hyde, now works for Creative Assembly developing hit titles such as Halo Wars and Halo Wars 2. Here he explains how maths has helped him to land his dream job…

Try out this maths puzzle set by St John’s maths tutor Dr David Seifert. If you send your answers in to inspire@sjc.ox.ac.uk you might even win a goodie bag!

How to earn billions by giving something away for free

St John’s Economics tutor Dr Kate Doornik explains the pricing strategy behind the incredibly successful ‘Fortnite: Battle Royale’. Originally given away for free, it is expected to make over $3 billion in sales in 2018…

# Tom Rocks Maths Episode 08

The final episode in season 1 of Tom Rocks Maths on Oxide Radio – Oxford University’s student radio station – with very special guests Jon and Nick discussing everything from the number of stickers needed to cover the Earth, to different types of infinity, via a new name for the world’s smallest number. Plus, a mammoth quiz to end the season in style and music from Nirvana and Soundgarden. This is maths, but not as you know it…

# Cannibals and hats

Time for the next puzzle in the new feature from Tom Rocks Maths – check out the question below and send your answers to @tomrocksmaths on Facebook, Twitter, Instagram or via the contact form on my website. The answer to the last puzzle can be found here.

You are walking through the jungle with two friends when all of a sudden you are attacked by a group of cannibals. Fortunately, they do not eat you straightaway, but instead devise a puzzle that you must solve to avoid being eaten. The setup is as follows:

- You are each tied to a pole such that you can only see forwards. The poles are placed in a line such that the person at the back can see the two people in front of them, the person in the middle can see one person in front of them, and the person at the front cannot see anyone else. See diagram below.

- The cannibals produce five hats: 3 are black and 2 are white. You are all then blindfolded and a hat is placed on each persons head at random. The other two hats are hidden.
- The blindfolds are removed and you are told that you will be set free provided that one of the group can correctly guess the colour of the hat that they are wearing. An incorrect guess will cause you all to be eaten.
- The person at the back says that they do not know the colour of their hat. The person in the middle says that they also do not now the colour of their hat. Finally, the person at the front says that they DO know the colour of their hat.

**The questions is: what colour hat is the person at the front wearing and how did they know the answer?**

The answer will be posted in a few weeks along with the next puzzle – good luck!

# The Tragic History of Mathematicians

The second puzzle in the new feature from Tom Rocks Maths – check out the question below and send your answers to me @tomrocksmaths on Twitter, Facebook, Instagram or via the contact form on my website. The answer to the first puzzle can be found here.

Below are portraits of four famous mathematicians from history that have all died in tragic circumstances. Your task is to match up the mathematician with one of the following causes of death:

- Shot in a duel
- Pushed overboard from a ship
- Suicide
- Lost his mind

Bonus points for explaining the work of any of the mathematicians shown. Good luck!

WARNING: answer below image so scroll slowly to avoid revealing it accidentally.

Answer:

a. Hippasus – Pushed overboard from a ship for his discovery and subsequent proof that the square root of 2 is an irrational number (cannot be written as a fraction).

b. Cantor – Lost his mind after discovering that there are more one type of infinity. For example the positive integers (whole numbers) are countably infinite, whilst the real numbers are uncountably infinite.

c. Boltzmann – Suicide. He is most famous for the development of statistical mechanics which explains how the properties of atoms determine the physical properties of matter.

d. Galois – Shot in a duel after being involved in a ‘love triangle’. Fortunately he wrote down all of his work/thoughts the night before which now forms the basis of Galois theory.

# The Game of Life

The simple mathematical game that inspired the pattern on the facade at Cambridge North station – live interview with BBC Radio Cambridgeshire.

**Examples** (image credits: Wikipedia)

Stable ‘still-life’ patterns that remain fixed for every turn.

Block Beehive Boat Loaf Tub

‘Oscillators’ that cycle through a number of designs repeating every few turns.

Beacon (period 2) Blinker (period 2) Toad (period 2)

Pulsar (period 3) Pentadecathlon (period 15)

Spaceships that travel across the board forever.

Glider Lightweight Spaceship

You can play the game of life for yourself online here.