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21 replies to this topic

#1 bonanova

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Posted 25 January 2008 - 12:17 PM

[1] Standard version of a classic

A king wishes to choose the man his daughter will marry.
She has three suitors: a Knight, a Knave, and a Commoner - whom the King wants to avoid.
The king does not know which man is which, and the suitors do not know each other.
But the king knows Knights always speak the truth, Knaves always lie; while Commoners respond as they please.
The king asks each man one yes/no question, then chooses the groom.
What are his questions, and how should he choose?

[2] Standard version with a twist

Now suppose the three suitors know each other.
Find a new strategy for the king to ask a question of just two of the three suitors to pick the groom.

[3] Making it a little harder

Find a strategy for the king to ask questions of only one suitor, but there can be two questions.

[4] The Puzzle Master special

Find a strategy for the king to ask only one yes/no question and only of one suitor.

-------------------
Edit for clarity: "ask questions of one suitor" means "ask one suitor a question"
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#2 roolstar

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Posted 25 January 2008 - 02:21 PM

Spoiler for version 1

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#3 roolstar

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Posted 25 January 2008 - 02:50 PM

Spoiler for version 2

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#4 roolstar

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Posted 25 January 2008 - 02:57 PM

Find a strategy for the king to ask questions of only one suitor, but there can be two questions.


Find a strategy for the king to ask only one yes/no question and only of one suitor.



What do you mean by of only one suitor...

Do you mean about only one suiter...?

or to only one suiter...? <= This is how I understood it first.

because this may mean that the answer I provided for version 2 is not suitable! :huh:

Thanks for clarifying...

Edited by roolstar, 25 January 2008 - 03:01 PM.

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#5 unreality

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Posted 25 January 2008 - 07:13 PM

But the king knows Knights always speak the truth, Knaves always lie; while Commoners respond as they please.


Does this mean the Commoner wants to be married to the Princess and would thus answer the best way that he thinks he could be married to her? Does he try his hardest to make sure the King picks him?

Or do you mean he basically answers randomly 'YES' or 'NO' for the purposes of this riddle?
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#6 bonanova

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Posted 25 January 2008 - 11:06 PM

What do you mean by of only one suitor...

Do you mean about only one suiter...?

or to only one suiter...? <= This is how I understood it first.

because this may mean that the answer I provided for version 2 is not suitable! :huh:

Thanks for clarifying...

I mean "of" in the sense you mean "to".
The king asks one suitor two questions.
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#7 bonanova

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Posted 25 January 2008 - 11:09 PM

Does this mean the Commoner wants to be married to the Princess and would thus answer the best way that he thinks he could be married to her? Does he try his hardest to make sure the King picks him?

Or do you mean he basically answers randomly 'YES' or 'NO' for the purposes of this riddle?

Well I think you can't trust him to answer in any way that you can anticipate.
I see how "answers as he pleases" might be taken to mean "answers to his advantage",
but let's rule that out and assume nothing about his motivation - or that he has no motivation.
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The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

#8 unreality

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Posted 26 January 2008 - 01:29 AM

Alright, thanks :D

I will get working on this
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#9 roolstar

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Posted 27 January 2008 - 03:45 PM

Now suppose the three suitors know each other.



Is this for all the rest of the versions? [3] & [4]?

Sorry for all the question, but I just don't want to start on the wrong route......

Edited by roolstar, 27 January 2008 - 03:47 PM.

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#10 roolstar

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Posted 27 January 2008 - 04:14 PM

Spoiler for Version &#91

Edited by roolstar, 27 January 2008 - 04:17 PM.

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