A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet 6 inhabitants: Aiden, Evelyn, Michael, Matthew, Avery, and Isabella. Aiden commented, "Evelyn is a knave or Isabella is a knight". According to Evelyn, "Aiden is not a knave". According to Michael, "Avery is a knight and Matthew is a knight". Matthew asserted: "Aiden is not a knave". "Evelyn is not a knight," Avery declared. Isabella told you that Michael is a knave and Aiden is a knight. So who is a knight and who is a knave?
Aiden is a knight, Evelyn is a knight, Michael is a knave, Matthew is a knight, Avery is a knave, and Isabella is a knight.
(1) Aiden is a knight
(2) Evelyn is a knight
(3) Michael is a knave
(4) Matthew is a knight
(5) Avery is a knave
(6) Isabella is a knight
Assume Aiden is a knight. No contradiction is found in their claim that Evelyn is a knave or Isabella is a knight. Assume Evelyn is a knight. No contradiction is found in their claim that Aiden is not a knave. Assume Isabella is a knight. No contradiction is found in their claim that Michael is a knave and Aiden is a knight. Michael cannot be a knight, because this would contradict the claim of Isabella that Michael is a knave and Aiden is a knight. Assume Michael is a knave. No contradiction is found in their false claim that Avery is a knight and Matthew is a knight. Avery cannot be a knight, because this would contradict the claim of their own that Evelyn is not a knight. Assume Avery is a knave. No contradiction is found in their false claim that Evelyn is not a knight. Assume Matthew is a knight. No contradiction is found in their claim that Aiden is not a knave.