Puzzles

How do you solve probability problems that appear to have more than one correct answer?

The counterintuitive solution to this month’s puzzle raises philosophical questions about randomness and information.

Quanta’s new puzzle column asks you to believe the seemingly impossible — that you can win at a number guessing game with absolutely no information.

Solve this variation of Thomas Kirkman’s famous 1850 puzzle by arranging girls in walking groups. And think fast — the clock is ticking.