A particular house has two rooms. If you're in one of the rooms you cannot look into the other. In one of the rooms there are three lamps which are connected to three switches located in the other room. For each lamp there is a separate switch. You are in the room with the switches. You are allowed to go only once in the room with the lamps. How can you find out to which lamp each switch is connected?
The pieces with the same color in left figure have the same size as in the ones in the right figure. In the right image the pieces are only ordered differently. How to explain the hole in the right image?
