Blog posts with problems to get your brain going! You get a new problem every fortnight and the solutions are published later.

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The next problem is scheduled for Sunday, 7th of March.

_{You may notice some problems are missing... I'm still migrating articles from my old blog.}

Some people are standing quiet in a line, each person with a hat that has one of two colours. How many people can guess their colour correctly?

In this problem you have to devise a strategy to beat the computer in a "guess the polynomial" game.

This simple problem is an example of a very interesting phenomenon: if you have a large enough "universe" to consider, even randomly picked parts exhibit structured properties.