All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Logic
Light bulb (Posted on 2002-05-16) Difficulty: 2 of 5
A light bulb is hanging in a room. Outside of the room there are three switches, of which only one is connected to the lamp. In the starting situation, all switches are off and the bulb is not lit.

You are allowed to enter the room only once (the bulb is not visible from outside). How can you determine which of the three switches turns on the light bulb?

See The Solution Submitted by Half-Mad    
Rating: 3.2500 (24 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Some Thoughts Solution... Kind of... | Comment 13 of 17 |

I've heard of a puzzle like this before, where there were three lights instead of one... but here goes!

I think that  you need to turn all of the lights on, but at different times with about half-an-hour in between, then go into the room after about another half-hour. So long as the bulb isn't some last-super-super-long ones, you should be able to judge depending on the temperature which switch is THE switch.


  Posted by Stephen Ticsay on 2005-04-15 01:37:27
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (11)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information