[Monday]

Originally Posted by Gypsy & Me

Here's one....

In the basement there are 3 light switches in the off position. Each switch controls 1 of 3 light bulbs on the floor above. You may move any of the switches, but you may only go up stairs one time. How can you determine which switch controls each light?

Turn any switch "ON" for 5 minutes, then turn that switch off & quickly turn on 1 of the others "ON".

go back upstairs and touch the 2 lights that were "OFF"...
One of them will be hot b/c it was on for 5 minutes ...

Then you can see that the HOT bulb was controlled by the first swtich you turned "ON" ...

the light that is now on, is controlled by the last switch you turned "ON" ...


The COLD bulb that is "OFF" is controlled by the only switch left ...