A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet 6 inhabitants: Harper, Jackson, Scarlett, Abigail, Oliver, and Daniel. Harper stated, "Scarlett is a knight and Daniel is a knight". Jackson noted, "Abigail is a knight and Abigail is a knave". In Scarlett's words: "Jackson is not a knight". According to Abigail, "If Oliver is a knight then Harper is a knight". In a statement by Oliver: "Jackson is a knave and Daniel is a knight". Daniel expressed that Scarlett is a knight. So who is a knight and who is a knave?
Harper is a knight, Jackson is a knave, Scarlett is a knight, Abigail is a knight, Oliver is a knight, and Daniel is a knight.
(1) Harper is a knight
(2) Jackson is a knave
(3) Scarlett is a knight
(4) Abigail is a knight
(5) Oliver is a knight
(6) Daniel is a knight
Assume Harper is a knight. No contradiction is found in their claim that Scarlett is a knight and Daniel is a knight. Assume Scarlett is a knight. No contradiction is found in their claim that Jackson is not a knight. Jackson cannot be a knight, because this would contradict the claim of their own that Abigail is a knight and Abigail is a knave. Assume Jackson is a knave. No contradiction is found in their false claim that Abigail is a knight and Abigail is a knave. Assume Abigail is a knight. No contradiction is found in their claim that If Oliver is a knight then Harper is a knight. Assume Oliver is a knight. No contradiction is found in their claim that Jackson is a knave and Daniel is a knight. Assume Daniel is a knight. No contradiction is found in their claim that Scarlett is a knight.