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

Home > Logic > Liars and Knights
A grok is a grok is a ... ? (Posted on 2007-06-29) Difficulty: 3 of 5
One day you meet three persons, each either a Knight or a Liar. You ask "How many of you are knights?", and the first person answers "Grok!".

Not understanding, you ask the second one "What does 'Grok' mean?", and he answers "One", but then the third one cries out "That's false!".

What can you tell about each person, if anything?

No Solution Yet Submitted by Federico Kereki    
Rating: 3.0000 (4 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution Solution | Comment 5 of 11 |

Let the first, second and third person be respectively denoted by A, B and C. Now, C's statement implies that B is a liar. Since no liar will ever truthfully identify a fellow liar, it follows that C is a knight,so that B is a liar.

If A is a knight, then A has truthfully identified the total number of knights as 2, and accordingly, "grok" will mean "two" in that situation.

If A is a liar, then "grok" can either mean mean either of the numbers "zero" or "three". It is also possible that"grok" do not represent numbers, but can represent any given thing. For example, "grok" can denote the name of a person/place etc.

Consequently, summarising we have:

* Second Person... Liar
* Third Person ... Knight
* First Person....Knight or Liar.
* "grok" means "two" iff the First Person is a Knight.

Edited on June 30, 2007, 2:57 pm
  Posted by K Sengupta on 2007-06-29 23:26:20

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 (10)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information