Logic puzzles and brain teasers

Train reasoning with classic and modern logic problems — by difficulty, with hints and full solutions.

Difficulty

All puzzles

Three guests pay for a room, but a strange calculation seems to make one dollar disappear.

One guard always lies, one always tells the truth. Which door leads to freedom?

A farmer must cross a river with a fox, a chicken, and grain. How can he do it without losing anything?

Lily pads double every day. If the pond is full on day 48, on what day is it half full?

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