5 puzzles from Édouard Lucas, each explained in a minute and credited to the original work. Free on Savvy.
Move a stack of discs from one peg to another, one disc at a time, never placing a larger disc on top of a smaller one, using a spare peg to help. Legend has it that monks in a tem…
— Édouard Lucas, Tower of Hanoi
Seat men and women alternately around a circular table, with the women's seats already fixed, so that nobody ends up next to their own husband or wife. For four couples, how many v…
— Édouard Lucas, Théorie des Nombres
Stack cannonballs into a square pyramid: 1 ball on top, 4 beneath that, 9 beneath that, and so on down to a square base N balls per side. Is there any pyramid height for which that…
— Edouard Lucas, Cannonball problem
On a grid of dots, two players take turns drawing one line between two adjacent dots. Whoever draws the fourth side of a small box claims it and immediately takes another turn. Onc…
— Édouard Lucas, Dots and Boxes
Three pegs hold a stack of discs of different sizes. Move the whole stack from one peg to another, one disc at a time, never placing a larger disc on top of a smaller one. Édouard …
— Édouard Lucas, Récréations mathématiques