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brain teaser question - switches and lights [Copy link] 中文

Rank: 4

Post time 2005-5-26 17:43:54 |Display all floors
Please leave the thread if you are not interested in answering the question.  Flaming or fights are kindly invited to go to the other threads and I will meet you there.

Those interested forumites please ignore any potential flamings or fights in case there are any

please think about it and post your answers below.  My answer will be posted in 24 hours

There is a completely sealed room with no windows.  There are 3 lights inside the room.

There are 3 switches outside the room, each controlling each of the 3 lights inside the room.

You cannot see both the switches and the lights at the same time

You can can only enter the room once and you are by yourself.

How can you find out which switch controls which light?


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Rank: 4

Post time 2005-5-26 17:55:05 |Display all floors

Come on! Give us a break!

Stop spamming on this forum with such a stupid IQ question.

I used to ask this question to a 9 yr old little girl living in neighbourhood, she gave me the right answer within 2 minutes!

Unless you don't know the answer by yourself.


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Rank: 4

Post time 2005-5-26 18:01:08 |Display all floors

Here is a solution

Step 1# Turn switch No.1 on for 5 minutes and turn it off.

Step 2# Turn switch No.2 and open the door.

The bulb which is on light belongs to switch No.2.

The bulb which is hot belongs to swith No.1

The bulb left belongs to switch No.3

Stupid Fioretta!

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