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Lateral Thinking - Brain Teasers
Lights 1,2 and 3 --- Switches A, B and C

Tue Feb 05, 2013 6:40 pm  by GRhein

Adjacent, plain white rooms X and Y are connected by a single door. There are no windows or additional doors in either room. There is no way to peak into one room from the other.

-In room X there are three light bulbs: 1, 2 and 3.
-In room Y there are three light switches: A, B, and C.
-Each light bulb is controlled by one and only one light switch.
-When a switch is flipped upwards, it's corresponding bulb is on.
-We do not know which light switches turn on which light bulbs.

How can you determine which light switch controls which bulb, when:
-You may choose to begin either in room X or Y.
-You may pass through the door only once.
-Once you have chosen to open the door, you must pass through, and cannot look back into the origin room after peering into the destination room.
-Any bulb/switch can be on or off at the outset.
-These are sturdy bulbs and switches: immune to short circuiting, burning out, and other mechanical failures.

Thu Feb 14, 2013 2:29 pm  by AnGuSxD

I turn on Switch A and turn it of again after some minutes.
I turn on Switch B and let it be turned on.
And I don't touch Switch C.

Now I go to the next room, the Bulb that is on belongs to Switch B, the Bulb that is off but Hot belongs to Switch A and the Bulb that is off and cool belongs to Switch C.

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