Monday puzzle: pairs of cards
Let's play a game of chance. I have in my hand a standard 52 card deck. What I will do is flip over two cards at a time. If the two cards happen to be red, then you get the pair. If the two cards are black, then I get the pair. ...

Puzzle: escaping a thief
There's an interesting article at Fast Company that shows how games can help with strategic decision making. The US Navy is doing something very fascinating. It is launching an online multi-player game as a way to learn innovative tactics and strategies to combat Somali pirates. Time will tell if the ...

Video roulette math puzzle
I recently heard of a game called Netflix roulette where people pick a video at random and watch it regardless of the result. It got me thinking about probability and I came up with the following problem. Bob loves the TV show Law & Order. Each day he picks an episode at ...

Ants on a Triangle Puzzle
This is a fun little puzzle I was sent the other day. On a triangle, each corner has an ant. Each ant starts to move on an edge towards another corner, chosen at random. What is the chance that none of the ants collide? Can you solve it? I will post my ...

Math Problem: pizza topping combinations
One of my favorite commercials is an old ad for Little Caesar's pizza. They were offering a deal for ordering 2 pizzas, with up to 5 toppings on each. The commercial emphasized how customers could order pizzas in many different possibilities. The question is: exactly how many distinct ways are there to order ...

The world’s best tortilla puzzle
This is a brain teaser that I have adapted from the pizza puzzle found in the book The World's Best Puzzles. You start out with a whole, circular tortilla as pictured above. Your job is to divide the tortilla into eight equal pieces, using only cuts made in a straight line. What is ...

One mile south, one mile east, one mile north – a classic puzzle
I was having dinner with a friend the other day. We were talking about my writing, and out of the blue he asked me what my favorite puzzle was. A lot of the puzzles I wrote about on this site came to mind, including The hat puzzle A mystery Sherlock Holmes couldn't solve, ...

A fun card puzzle
I came across a good brain teaser at this site: A pack of cards has 52 cards. You are in a dark room with this pack of cards. You have been told that inside the pack there are 42 cards facing down, 10 cards facing up. You have been asked to ...

Guess the number – a game theory puzzle
I came across a highly amusing puzzle in Impossible?: Surprising Solutions to Counterintuitive Conundrums. What distinguishes this brain teaser from other "guess my number" puzzles is the method of solution. The answer is not an arithmetic trick or a mathematical sleight of hand like in your age by restaurant math. The puzzle ...

How to avoid the winner’s curse using game theory
I've made a huge mistake--GOB and others from Arrested Development Strangely, in many auctions it is a huge mistake to win. Winning can either be unprofitable or less profitable than expected, kind of like a Pyrrhic victory. The tendency of the winner to overpay is more commonly known as the winner's ...

The Russian roulette puzzle
Can probability theory save your life? Perhaps not in usual circumstances, but it sure would help if you found yourself playing a game of Russian roulette. Today's article covers a couple of variations on the Russian roulette puzzle, which is occasionally asked as an interview brain teaser. Puzzle 1: Single bullet I received ...