Knaves, a conditional, and a head count
Asked at DRW, Akuna
On the island of knights (always truthful) and knaves (always lying), four residents each make a claim:
- Ada: "Bo and Cy are both knaves."
- Bo: "If I am a knight, then Dev is a knight."
- Cy: "At least one of Ada and Dev is a knave."
- Dev: "Exactly three of us are knights."
Sort each of the four into knight or knave.
Your answer
This one is open-ended. Work it through, then check your reasoning against the full solution.