A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet 6 inhabitants: Scarlett, Riley, Ethan, Penelope, Samuel, and Aiden. Scarlett commented, "Samuel is a knave". Riley asserted: "Aiden is not a knave". "If Riley is a knight then Samuel is a knight," Ethan declared. Penelope remarked, "Aiden is a knight or Riley is a knave". "Aiden is a knave," Samuel mentioned. Aiden told you that Aiden is a knight if and only if Samuel is a knave. So who is a knight and who is a knave?
Scarlett is a knight, Riley is a knight, Ethan is a knave, Penelope is a knight, Samuel is a knave, and Aiden is a knight.
(1) Scarlett is a knight
(2) Riley is a knight
(3) Ethan is a knave
(4) Penelope is a knight
(5) Samuel is a knave
(6) Aiden is a knight
Assume Scarlett is a knight. No contradiction is found in their claim that Samuel is a knave. Samuel cannot be a knight, because this would contradict the claim of Scarlett that Samuel is a knave. Assume Samuel is a knave. No contradiction is found in their false claim that Aiden is a knave. Assume Aiden is a knight. No contradiction is found in their claim that Aiden is a knight if and only if Samuel is a knave. Assume Riley is a knight. No contradiction is found in their claim that Aiden is not a knave. Ethan cannot be a knight, because this would contradict the claim of their own that If Riley is a knight then Samuel is a knight. Assume Ethan is a knave. No contradiction is found in their false claim that If Riley is a knight then Samuel is a knight. Assume Penelope is a knight. No contradiction is found in their claim that Aiden is a knight or Riley is a knave.