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I don't know. (Posted on 2006-02-16) Difficulty: 2 of 5
ou are a logician in training for the police, and the time has come to take the certification test. The police chief brings you the test one morning, and says, "I must warn you, this is your only chance at the certification test; If you fail, you must keep training for another year before you can take it again."
- Five suspects were interrogated for a bank robbery.
- Each suspect was either a knight, a knave, or a liar.
- Knights always tell the truth.
- Liars always lie.
- Knaves strictly alternate truths and lies with each statement.
- Police have evidence that suggests the perpetrator acted alone.
- Police have evidence that suggests the perpetrator acted alone.

>During the interrogation, two questions were asked (consecutively) of each of the five suspects. Each suspect heard the other suspects' responses, and none of them made a statement between his or her two answers. Here are the two questions and their responses.

"Did you rob the bank?"
A: No.
B: No.
C: No.
D: Yes.
E: Yes.

"Who robbed the bank?"
A: E.
B: A.
C: l don't know.
D: E.
E: A.

The interrogators mentioned that something about their statements didn't seem quite right. The police chief adds, "The only hints I can give you are that C is not a knight and that there is only one correct answer. I'll be back in 24 hours to ask you who robbed the bank."

No Solution Yet Submitted by Dustin    
Rating: 3.4286 (7 votes)

Comments: ( You must be logged in to post comments.)
  Subject Author Date
Some ThoughtsSolutionDej Mar2006-05-08 11:26:52
re: Another change in Problem text?Sami Jouppila2006-03-12 16:50:42
Another change in Problem text?Kenny M2006-03-12 14:05:24
re(3): Solution using correct version of the puzzletomarken2006-03-08 22:15:23
re(2): Solution using correct version of the puzzleAvin2006-03-08 12:29:27
re: Solution using correct version of the puzzleHighway62006-03-08 10:56:42
SolutionSolution using correct version of the puzzleAvin2006-03-08 10:24:47
Hints/TipsNo SubjectDustin2006-03-07 16:09:40
random and probably pointless thoughts.Highway62006-03-07 15:08:18
tying together two of the several loose ends.Cory Taylor2006-03-07 10:54:00
Some Thoughtsmaybe "I dont know"Highway62006-03-06 16:47:46
re: Possible - with inspiration from others...tomarken2006-03-02 19:20:13
SolutionPossible - with inspiration from others...Kenny M2006-03-02 18:15:17
re: A different approach and solutionCory Taylor2006-03-01 16:51:24
SolutionA different approach and solutiontomarken2006-03-01 11:03:29
solutionsalil2006-02-26 01:26:15
solutionimakolata2006-02-22 05:39:41
Compilation of oddities in this problem:Avin2006-02-21 15:20:48
Solutionre: Reply to AvalonXQPenny2006-02-19 16:22:24
re: SolutionSeaCalMaster2006-02-19 12:30:26
Solutionsalil2006-02-19 10:23:40
re(2): A potential answerAvalonXQ2006-02-19 02:18:46
Three things...Eric2006-02-18 21:41:35
re: A potential answerSeaCalMaster2006-02-18 19:18:13
SolutionA potential answerAvalonXQ2006-02-18 18:52:13
Hints/TipsNo SubjectAvalonXQ2006-02-18 18:46:24
Questionre: C's AnswerSeaCalMaster2006-02-18 12:54:50
QuestionC's AnswerVernon Lewis2006-02-18 08:59:03
Words are all importantKenny M2006-02-17 21:05:19
re(5): InsolublePenny2006-02-17 19:52:56
re(4): InsolublePenny2006-02-17 19:42:01
re: SolutionJustin2006-02-17 19:32:22
Another tack..Kenny M2006-02-17 17:40:09
re(4): InsolubleAvalonXQ2006-02-17 17:10:22
re(3): InsolubleAvalonXQ2006-02-17 17:07:28
re(2): InsolublePenny2006-02-17 13:41:52
re: I do knowVernon Lewis2006-02-17 12:58:14
I do knowBob Smith2006-02-17 12:41:34
re: I don't buy thePenny2006-02-17 12:26:09
I don't buy the "lack of knowledge" solution...Avin2006-02-17 11:12:27
re: InsolublePenny2006-02-17 08:24:30
SolutionInsolubleAvalonXQ2006-02-17 04:23:59
SolutionSolutionPenny2006-02-16 23:33:03
Hints/TipsSomething strange...SeaCalMaster2006-02-16 21:17:27
re: Possibly-maybe-perhaps...amended & appendedKenny M2006-02-16 20:18:35
Some ThoughtsPossibly-maybe-perhaps...Kenny M2006-02-16 19:51:34
re(2): Immediate Knowledge - rebuttleCory Taylor2006-02-16 18:29:46
Hints/TipsHmmmm - Very InterstingVernon Lewis2006-02-16 18:20:57
SolutionSolutionGeoff2006-02-16 17:01:28
re: Immediate Knowledge - rebuttleLeming2006-02-16 16:13:59
Some ThoughtsImmediate KnowledgeCory Taylor2006-02-16 15:37:49
Some ThoughtsMissing something. . . or am I?Leming2006-02-16 14:40:49
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