8+ Logic Puzzles to Solve

Four people need to cross a bridge at night. They have one torch. The bridge can only hold two people at a time. Person A takes 1 minute to cross, B takes 2 minutes, C takes 5 minutes, and D takes 10 minutes. How can they all cross in 17 minutes?

You have 12 identical-looking coins, but one is either slightly heavier or lighter than the others. You have a balance scale and can use it only three times. How do you identify the false coin?

A prisoner is told he will be hanged on a morning when he will not expect it. He reasons he cannot be hanged, but he is. How?

How can you place 8 queens on a chessboard so that no queen can attack another?

Three light switches are outside a closed door. Inside the room are three light bulbs, each controlled by one switch. You can only enter the room once. How can you determine which switch controls which bulb?

A king has 1000 wine bottles, and he discovers that one is poisoned. He has 10 prisoners to help him identify the poisoned bottle. The poison takes effect exactly 24 hours after consumption. How can he identify the poisoned bottle in just one day?