Gerolamo Cardano: 2 puzzles worth knowing

2 puzzles from Gerolamo Cardano, each explained in a minute and credited to the original work. Free on Savvy.

Nine rings, looped on a bar — remove them all, and you'll need over 300 moves
A sequence of rings hangs looped on interlinked pillars, threaded through a bar. The rules only let you slide one ring at a time under a strict condition based on the rings next to…
— Gerolamo Cardano, De subtilitate
Renaissance mathematicians dueled in public to solve a 'forbidden' equation
In 1535, Antonio Fior challenged Niccolò Tartaglia to a contest: each gave the other thirty problems to solve. All of Fior's problems required cubic equations of the form x³ + px =…
— Gerolamo Cardano, Ars Magna

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