A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet 6 inhabitants: Isabella, Amelia, Joseph, Riley, Victoria, and James. Isabella told you that If Amelia is a knave then Joseph is a knave. Amelia was heard saying, "Victoria is a knave". Joseph said that Isabella is a knight or James is a knight. Riley told you that Isabella is a knight and Joseph is a knight. Victoria commented, "Riley is not a knight". James expressed that Amelia is a knave and Isabella is a knight. So who is a knight and who is a knave?
Isabella is a knight, Amelia is a knight, Joseph is a knight, Riley is a knight, Victoria is a knave, and James is a knave.
(1) Isabella is a knight
(2) Amelia is a knight
(3) Joseph is a knight
(4) Riley is a knight
(5) Victoria is a knave
(6) James is a knave
Assume Isabella is a knight. No contradiction is found in their claim that If Amelia is a knave then Joseph is a knave. Assume Amelia is a knight. No contradiction is found in their claim that Victoria is a knave. Victoria cannot be a knight, because this would contradict the claim of Amelia that Victoria is a knave. Assume Victoria is a knave. No contradiction is found in their false claim that Riley is not a knight. Assume Riley is a knight. No contradiction is found in their claim that Isabella is a knight and Joseph is a knight. Assume Joseph is a knight. No contradiction is found in their claim that Isabella is a knight or James is a knight. James cannot be a knight, because this would contradict the claim of their own that Amelia is a knave and Isabella is a knight. Assume James is a knave. No contradiction is found in their false claim that Amelia is a knave and Isabella is a knight.