Logic Puzzles

Here are some green eyed monsters:

http://ed.ted.com/lessons/the-famously-difficult-green-eyed-logic-puzzle-alex-gendler

New one:

There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position.
How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

Izoshua wrote: New one:

There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position.
How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

You can put tape above the light switches and write on them when you first buy the house. That way you don't have to worry about it #logic

You could also try to grab 2 other people and each one of you turn on a light switch. #alsologic

I already know the answer to the lightbulb puzzle, but I'll leave it a while before posting so I don't ruin it for anyone that wants to try

Alright, this one's for you then Edan. Hopefully you haven't solved this one yet.

Three people were taken captive by a hostile Indian tribe. According to tribe’s custom they had to pass an intelligence test, or die. The chieftain showed 5 headbands – 2 black and 3 white. The 3 men were blindfolded and positioned one after another, face to back. The chief put a headband on each of their heads, hid two remaining headbands, and removed their blindfolds. So the third man could see the headbands on the two men in front of him, the second man could see the headband on the first, and the first could not see any headbands at all.
According to the rules any one of the three men could speak first and try to guess his headband color. And if he guessed correctly – they passed the test and could go free, if not – they failed. It so happened that all 3 of them were prominent logicians from a nearby academy. So after a few minutes of silence, the first man in the line said: "My headband is ...".
What color was his head band? Why?

Izoshua wrote: Alright, this one's for you then Edan. Hopefully you haven't solved this one yet.

Three people were taken captive by a hostile Indian tribe. According to tribe’s custom they had to pass an intelligence test, or die. The chieftain showed 5 headbands – 2 black and 3 white. The 3 men were blindfolded and positioned one after another, face to back. The chief put a headband on each of their heads, hid two remaining headbands, and removed their blindfolds. So the third man could see the headbands on the two men in front of him, the second man could see the headband on the first, and the first could not see any headbands at all.
According to the rules any one of the three men could speak first and try to guess his headband color. And if he guessed correctly – they passed the test and could go free, if not – they failed. It so happened that all 3 of them were prominent logicians from a nearby academy. So after a few minutes of silence, the first man in the line said: "My headband is ...".
What color was his head band? Why?

This was good

Answer:

Izoshua wrote: New one:

There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position.
How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

So here's the answer...

indeed.

Here's another kinda common one, but in case someone has yet to solve it:

You have 9 balls that are all the same size, and an old fashioned balance scale. One of the balls weighs slightly more than the others. You can only use the scale twice. How do you find the heavier ball?

Izoshua wrote: Here's another kinda common one, but in case someone has yet to solve it:

You have 9 balls that are all the same size, and an old fashioned balance scale. One of the balls weighs slightly more than the others. You can only use the scale twice. How do you find the heavier ball?

Kinda like this:
https://www.youtube.com/watch?v=X2xlQaimsGg