Tuesday, 21 August 2007

A Bit of Fun...


My postings have been a bit depressing recently so I thought a little Smullyanesque/Newheiseran Logic puzzles might relieve the tension.

You've died and are strolling through purgatory on your way to Heaven.

Now in order to get to heaven you must climb many hundreds of flights of stone stairs,
But in front of each staircase stand three individuals who will not let you pass them by;
unless you identify their true nature :

Each time all three look human , But One is an Angel who always tells the truth, One a Demon who always lies, and the last one is Human who can lie or be honest accoding to their whim.

The first staircase.

Person A: "I am an angel"

Person B: " I am not human"

Person C: " I am a demon"
Can you deduce who is whom ? whom is who ?
[Getting the 'Gist' of it ? they're quite simple when you think about them; but how often in a day do we really think ? These really help me wear my brain out before bedtime and the subsequent sleep is great - better than anything medication can provide]
[Thanks to the genius of Mark Newheiser]

2 comments:

gemoftheocean said...

Person A: "I am an angel"

Person B: " I am not human"

Person C: " I am a demon"

Fun puzzle.

C = human
B = Angel
A = Devil

Based on: all three statements have to fit the conditions. You have to rule out C being a demon, because demons always lie and a demon can't say he is a demon, C is either an angel or a human, by elimination. WE can further eliminate the angel from saying "C" - because the angel always tells the truth, and he can't be the devil. That leaves us with
"C" being the human, since he may tell either the truth or a lie.

Now that we have established who "C" is (i.e. the human) we are

left with the devil having to tell a lie. He can't say he is the human, because the statement "I am not a human" is a TRUE statement.
Ergo the devil has to say:
A: I am an angel -- which IS a lie.

Which leaves the angel for statement B: I am not a human -- a true statement and angels always tell the truth.

Thus, all three conditions are met.

Karen H. -- Gem of the Ocean

[Good quiz -- took me about 30 seconds -- and yes, thanks for putting up something lighter!]

Mark Newheiser said...

Hahahah, awesome. Glad to see someone else likes these puzzles... I have a set of them on my site here