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GeneralRe: Retiring to the South Pin
chriselst7-Jul-15 22:38
professionalchriselst7-Jul-15 22:38 
GeneralFree Running Monkeys PinPopular
Kevin Marois7-Jul-15 12:10
professionalKevin Marois7-Jul-15 12:10 
GeneralHeads Up... PinPopular
237417-Jul-15 11:06
237417-Jul-15 11:06 
GeneralRe: Heads Up... Pin
Richard Andrew x647-Jul-15 11:40
professionalRichard Andrew x647-Jul-15 11:40 
GeneralRe: Heads Up... Pin
Super Lloyd7-Jul-15 14:29
Super Lloyd7-Jul-15 14:29 
GeneralRe: Heads Up... Pin
RossMW7-Jul-15 15:04
professionalRossMW7-Jul-15 15:04 
GeneralRe: Heads Up... Pin
Daniel Pfeffer7-Jul-15 19:20
professionalDaniel Pfeffer7-Jul-15 19:20 
GeneralThe Three Switches Pin
Jörgen Andersson7-Jul-15 9:50
professionalJörgen Andersson7-Jul-15 9:50 
Downstairs in a house are three identical on-off switches.
One of them controls the lamp in the attic.
The puzzle is to work out which switch controls the lamp.

The rules are as follows.
You are allowed to manipulate the switches all you like, and then you are allowed a single trip to the attic.
How do you do it?

To clarify: When you are downstairs there is no way to see into the attic, or see reflected light from the attic.
Once you have gone to the attic you are not allowed back to the switches.
<edit>you can also assume original state of all switches to be off.</edit><hint>Otherwise it won't work</hint>

Note: If you already know the answer, or reads the newspaper where I nicked the puzzle from, then please don’t write it up immediately in the comments!
Give those who have never heard it before a chance to suffer, I mean enjoy finding the solution.
Wrong is evil and must be defeated. - Jeff Ello


modified 7-Jul-15 16:54pm.

GeneralRe: The Three Switches PinPopular
OriginalGriff7-Jul-15 9:56
mveOriginalGriff7-Jul-15 9:56 
GeneralRe: The Three Switches PinPopular
Jörgen Andersson7-Jul-15 10:56
professionalJörgen Andersson7-Jul-15 10:56 
GeneralRe: The Three Switches Pin
OriginalGriff7-Jul-15 11:05
mveOriginalGriff7-Jul-15 11:05 
GeneralRe: The Three Switches Pin
Jörgen Andersson7-Jul-15 11:09
professionalJörgen Andersson7-Jul-15 11:09 
GeneralRe: The Three Switches Pin
_Asif_7-Jul-15 20:07
professional_Asif_7-Jul-15 20:07 
GeneralRe: The Three Switches Pin
JimmyRopes7-Jul-15 19:18
professionalJimmyRopes7-Jul-15 19:18 
JokeRe: The Three Switches PinPopular
Richard Deeming7-Jul-15 10:16
mveRichard Deeming7-Jul-15 10:16 
GeneralRe: The Three Switches Pin
OriginalGriff7-Jul-15 10:34
mveOriginalGriff7-Jul-15 10:34 
GeneralRe: The Three Switches Pin
Jörgen Andersson7-Jul-15 10:50
professionalJörgen Andersson7-Jul-15 10:50 
GeneralRe: The Three Switches Pin
OriginalGriff7-Jul-15 11:07
mveOriginalGriff7-Jul-15 11:07 
GeneralRe: The Three Switches Pin
Jörgen Andersson7-Jul-15 11:13
professionalJörgen Andersson7-Jul-15 11:13 
GeneralRe: The Three Switches Pin
James Curran8-Jul-15 4:37
James Curran8-Jul-15 4:37 
GeneralRe: The Three Switches Pin
dandy727-Jul-15 10:32
dandy727-Jul-15 10:32 
GeneralRe: The Three Switches Pin
Jörgen Andersson7-Jul-15 10:49
professionalJörgen Andersson7-Jul-15 10:49 
GeneralRe: The Three Switches Pin
Ian Shlasko7-Jul-15 10:33
Ian Shlasko7-Jul-15 10:33 
GeneralRe: The Three Switches Pin
vtokar8-Jul-15 6:06
vtokar8-Jul-15 6:06 
GeneralRe: The Three Switches Pin
Richard Andrew x647-Jul-15 11:34
professionalRichard Andrew x647-Jul-15 11:34 

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