brain teasers | Boing Boing

brain teasers Challenge — can you get these cups unstuck? Mark Frauenfelder
triangles How many triangles do you see? David Pescovitz
numberphile Can you figure out what number comes next? Carla Sinclair
brain teasers Puzzle – how to ensure you get the quarter, not the penny Mark Frauenfelder
riddles Can you solve the seven planets riddle? David Pescovitz
brain teasers Excellent cheap puzzle book: The Moscow Puzzles: 359 Mathematical Recreations Mark Frauenfelder
brain teasers Can we wrap a 1x1x1 cube with the blue 3×3 piece of paper, cutting along some edges without disconnecting it? Mark Frauenfelder
brain teasers Can you solve the virus riddle? Mark Frauenfelder
brain teasers A hat puzzle Mark Frauenfelder
brain teasers Brain teaser: draw a cross inside the grid Mark Frauenfelder
brain teasers Puzzle: The Candy Thief Mark Frauenfelder
brain teasers The best place to sit in a "suicide circle" if you really don't want to die Mark Frauenfelder
brain teasers The best book of physics brain teasers Mark Frauenfelder
paradoxes The Missing Dollar puzzle from Martin Gardner's Aha! Gotcha book series Mark Frauenfelder
brain teasers Build this brain-teasing golf ball in a block of wood Mark Frauenfelder
paradoxes Saturday morning mind-benders: "Newcomb's Problem" and "Parfit's Hitchhiker" dilemma Mark Frauenfelder