The Blog
Puzzles
Logic puzzles and brain teasers with full worked answers.
Puzzles
The Three Doors Problem, Without the Shouting
A prize behind one of three doors, a host who knows where it is, and the switch that wins two times out of three.
Puzzles
A Knights and Knaves Starter Set
Knights always tell the truth and knaves always lie. Three short puzzles, worked out line by line, and a method that solves them all.
Puzzles
Two Doors, Two Guards, One Question
One guard always lies and the other always tells the truth. You get a single question. Here is the question, and why it works.
Puzzles
Four Cards, One Rule
A famous test of everyday logic that most people fail on the first try. Which two cards do you actually need to turn over?
Puzzles
The Three Switches Puzzle
Three switches, one closed room, one bulb, and only one trip through the door. The trick is noticing a clue that your eyes cannot see.