Who likes solving riddles? i love those ones in which when you find the correct answer you just feel soo stupid... lol
why don't we try each other with some?
here you go with the first one:
Imagine you are in a room with 3 switches. In an adjacent room there are 3 bulbs (all are off at the moment), each switch belongs to one bulb. It is impossible to see from one room to another. How can you find out which switch belongs to which bulb, if you may enter the room with the bulbs only once?