General Knowledge
Brain Teasers & Logic Puzzles Quiz 🧩
Riddles, paradoxes, and logic traps — only 10% of people get them all right.
Riddles, paradoxes, and logic traps — only 10% of people get them all right.
When Marilyn vos Savant published the correct Monty Hall solution in 1990, she received 10,000 angry letters — including from PhD mathematicians who were wrong. Logic puzzles have a remarkable power to confound even brilliant minds, because human intuition is often a very unreliable guide.
Each round presents 10 randomized multiple-choice questions drawn from a pool of 50, so every playthrough is different. You get instant feedback with explanations after each answer, plus a shareable score at the end.
You'll explore the Monty Hall Problem and why switching doors is mathematically correct, the Birthday Paradox and why 23 people gives you a 50% chance of a shared birthday, classic lateral thinking puzzles, famous paradoxes like the Ship of Theseus and the Grandfather Paradox, and fascinating facts about how the human brain processes logic and probability.
Yes — you should always switch. When you first pick a door, you have a 1/3 chance of being right. That means there is a 2/3 chance the car is behind one of the other two doors. When the host opens a losing door, that entire 2/3 probability concentrates on the remaining unopened door, so switching wins 2 out of 3 times on average.
The Birthday Paradox is the surprising statistical fact that in a group of just 23 people, there is roughly a 50% probability that at least two of them share the same birthday. Most people vastly underestimate this, guessing you would need around 180 people. The math works because you are comparing every possible pair of people, not each person against a specific birthday.
The puzzle known as "The Hardest Logic Puzzle Ever" was formulated by philosopher George Boolos in 1996. It involves three gods — one always tells the truth, one always lies, and one answers randomly — whose names you must determine by asking only three yes/no questions. The additional complication is that they answer in an unknown alien language where the words for "yes" and "no" are unknown to you.
Last updated: March 2026