Test your skills of deduction with the February 2023 edition of Riddle Me This: Knights or Knaves?
John was visiting an island where all the inhabitants are either Knights—always tell the truth, or Knaves—always lie.
John meets three of the inhabitants. A woman named Jackie, and two men named Ben and Don.
He asked Jackie “Are you a Knight?” She replied under her breath so he couldn’t hear her.
John asked Ben, who appeared to have heard the answer, “What did she say?”.
He replies, “She said yes, but she lied.” John then asked Don, “Did Ben lie?” He answers, “No he told the truth.”
Can you figure out who are the Knights and Knaves in the trio?
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“John was visiting an island where all the inhabitants are either Knights—always tell the truth, or Knaves—always lie.”
If this sentence had read “John was visiting an island where the inhabitants are either Knights or Knaves…” then there could indeed be a mix of Knights and Knaves.
However, the sentence reads that ALL the inhabitants are either Knights or Knaves.
It then becomes an island of Knaves as it is unable to be a mix.
My vote is that Jackie is a Knave and Ben and Don are Knights. Jackie can’t answer “No” regardless of which she is. Since her answer is “Yes” the solution lands on Ben being a knight since he correctly stated that she said “yes.” Since Don affirmed Ben’s statement he, too, must be a Knight. And don’t forget that the word “either” is ambiguous by nature. It can mean only one or only the other or it can mean both. I this case, the island is filled with both Knights and Knaves, not just all of one or all of the other…unless the author of the riddle is a Knave and everything in the statement is a lie. Hmmmm.