Hello, smurray1-ga!
I started reading your question and was sure that you were giving away
something critical to the 5th Harry Potter book so, having not even
completed the 4th book yet, I summoned my husband to screen the
question. He’s read all five and assures me that this question does
not even directly relate to the books. Phew!
This particular logic question is one that has been around for a LONG
time, only the variables change periodically. I found a number of
bulletin boards where people were discussing logic problems and found
the answer to this question on one of them
(http://www.faithforum.org/challenge/topic.asp?TOPIC_ID=3323). Here
goes . . .
Let’s label the cream puffs “A” and “B” for simplicity’s sake. Now
lets assume that A is the “safe” one and B is the “canary puff.”
Next, let’s consider Fred and George. There are two possibilities:
1. Fred is the truth-teller and George is the liar. Or,
2. Fred is the liar and George is the truth-teller.
There are two questions that could be asked of George, each revealing
the answer to this problem.
1. Would Fred say that “A” is safe? Or,
2. Would Fred say that “B” is safe?
I suppose that we could also ask the inverse (i.e., Would Fred say
that “A” is unsafe, etc.), but I didn’t include that question in the
list of possibilities, for simplicity’s sake.
Ok, let’s set up the different permutations. Using the above
possibilities there are four possibilities:
1. Fred = liar, George = truth-teller, “Would Fred say that A is
safe?”
2. Fred = truth-teller, George = liar, “Would Fred say that A is
safe?”
3. Fred = liar, George = truth-teller, “Would Fred say that B is
safe?”
4. Fred = truth-teller, George = liar, “Would Fred say that B is
safe?”
Now lets examine the results of each permutation:
1. Fred = liar, George = truth-teller, “Would Fred say that A is
safe?”
Fred’s natural answer, being the liar, would be “no.” George, being
the truth-teller would reflect that accurately by answering the
question with a “no.” Thus Hermione should act oppositely and eat
cream puff A.
2. Fred = truth-teller, George = liar, “Would Fred say that A is
safe?”
Fred’s natural answer, being the truth-teller would be “yes.” George,
being the liar would contradict that by answering the question with a
“no.” Thus Hermione should act oppositely again and eat cream puff A.
3. Fred = liar, George = truth-teller, “Would Fred say that B is
safe?”
Fred’s natural answer, being the liar, would be “yes.” George, being
the truth-teller would reflect that accurately by answering the
question with a “yes.” Thus Hermione should act oppositely and eat
cream puff A.
4. Fred = truth-teller, George = liar, “Would Fred say that B is
safe?”
Fred’s natural answer, being the truth-teller, would be “no.” George,
being the liar would contradict that by answering the question with a
“yes.” Thus Hermione should act oppositely and eat cream puff A.
As you can see, asking George to reveal Fred’s answer indicates that
Hermione should do the OPPOSITE in every case. Working out the above 4
scenarios using “B” as the safe cream puff will still give you the
answer that Hermione should act in opposition to George’s answers.
I hope that this is in fact the answer that you came up with. Thanks
for asking a great question and giving me a chance to work on this
brainteaser. If anything is unclear, please let me know!
Good luck,
Boquinha-ga
Google Search Strategy
One + question + logic + problem
://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=one+question+logic+problem
P.S. Out of curiosity, are you a Harry Potter fan? |
