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Three puzzles test whether the concept of infinity has purchase in the physical world.

Try these shortcuts for solving problems that seem to require a lengthy calculation.

Can you find a shortcut for solving problems that seem to require a lengthy calculation?

The famous Sleeping Beauty problem has divided probability theorists, decision theorists and philosophers for over 15 years. Puzzle columnist Pradeep Mutalik claims to have discovered the source of confusion.

For four game show variations of the hat puzzle, four clever ways to earn a better payoff than you might expect.

In three new variations of a famous logic puzzle, what are the best strategies for guessing the color of the hat on your head?

Assigning elements from a large collection to one of two categories can yield almost “magical” predictions about highly complicated problems without actually solving them.

In a geometrically designed social club, how do dancing, triangles and hexagons mix?

The solution to this month’s puzzle gets to the bottom of the famously ambiguous Sleeping Beauty probability problem.