Three friends, Anya, Keir, and Lucy have 3 different actions whenever they come across potentially new information.
One is a Scientist, they are always correct about which statements are true and will always tell the truth.
Another is a Psychiatrist, they like to test people by lying and seeing their reactions - however, they are misinformed.
The remaining one is a Lapidary, they will always try to tell the truth, but they are also misinformed.
They receive information (or misinformation) about each other's behaviours and make the following statements:
- Keir: Lucy is misinformed.
- Anya: I am not misinformed.
- Lucy: Anya is the Psychiatrist.
Determine the professions of the three friends in terms of the clues given above.
It took a few readings for me to get what the problem is asking. This is what I concluded:
The Scientist and the Psychologist tell the truth.
The Lapidary tells a lie.
"Misinformed" describes the Lapidary and the Psychologist.
"Not misinformed" describes the Scientist.
Only the Scientist or the Lapidary can claim "I am not misinformed." Therefore Anya cannot be the Psychiatrist.
Then Lucy's statement is false, which means she is the Lapidary.
Then Anya must be the Scientist and Keir is the Psychiatrist, both with true statements.