- You have 8 balls and one of them is heavier. You have a scale which you can use twice to find the heavy ball.
- The first one is too easy for some, so go on... Take a pen and paper for this one. You have 12 balls and one of them is heavier or lighter than the rest. You can use a scale 3 times to find the defective ball. Do not forget, you do not whether is is heavy or light...
- You are in front of a faucet. You have a bucket of 5 liters and a bucket of 3 liters. Can you obtain any amount of water from 1, 2, 3, 4 and 5 liters by only using these two buckets.
I borrowed these logic puzzles from my friend Liyakat's blog.