Light Switches

Bullet · New Member Joined: 07 Nov 2008 Posts: 11

This probably shouldn't be in the difficult section, but it is my first post so I'm sure I can be forgiven if it's too easy :p

Jake has an almost empty house with only 2 rooms. The first room contains 3 switches labeled A, B and C. These switches operate the 3 lights in the second room, labeled X, Y and Z. However Jake does not know for which light each switch is.

Jake will start in the first room with only the knowledge that each of the 3 lights are turned off. He may flick the switches as much as he wants, but may only go into the second room once.

As Jake is only allowed one visit to the second room, how can he determine which lights the switches A,B and C are for.

Vertabladehot2m · Guy Who Loves This Site Joined: 10 Nov 2006 Posts: 212

well he can turn one of the lights on first for a long period of time. then he turns it off and turns on another light for an even longer period of time. when he turns that one off, he can go into the second room and feel each of the light bulbs or whatever. whichever one is the hottest is the one that he turned off last, the one that is the second hottest is the one he turned on first, and the one without any heat is the one that he never flicked.

Bullet · New Member Joined: 07 Nov 2008 Posts: 11

Your pretty much right, just overcomplicated it a bit. He turns on A and B(for example), and after a few minutes turns off B. He can then go into the second room and the light operated by switch A will be on, the light operated by switch B will be warm, and the light operated by switch C will be cold.