A man has 5 pieces of chain that must be joined into a long chain. He can open ring 3 (first operation), link it to ring 4 (second operation), then unfasten ring 6 and link it to ring 7, and so on.
He could complete his task in 8 operations, but he wants to do it in 6. How does he do it? Riddle Answer
Here is a light switch. Note the order of the positions. If the light is now at medium and it is switched 3922 times what will be the position of the switch?
A building is being prepared for opening. People are decorating the building with 12 flags. At first they arrange the flags 4 to a side, as shown, but then they see that the flags can be arranged 5 to a side using only 12 flags. How?
You have 8 balls numbered 1, 3, 5, 7, 9, 11, 13 and 15. Select 3 balls and put them into the circles such that the sum of the numbers on them add up to 30.