A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet 6 inhabitants: Mia, Penelope, Victoria, Amelia, Henry, and Jacob. In a statement by Mia: "Penelope is a knight". Penelope noted, "If Amelia is a knight then Victoria is a knave". Victoria noted, "Mia is a knave if and only if Henry is a knave". "Jacob is not a knave" - Amelia. "Jacob is not a knave" - Henry. "Victoria is not a knave," Jacob claimed. So who is a knight and who is a knave?
Mia is a knight, Penelope is a knight, Victoria is a knave, Amelia is a knave, Henry is a knave, and Jacob is a knave.
(1) Mia is a knight
(2) Penelope is a knight
(3) Victoria is a knave
(4) Amelia is a knave
(5) Henry is a knave
(6) Jacob is a knave
Assume Mia is a knight. No contradiction is found in their claim that Penelope is a knight. Assume Penelope is a knight. No contradiction is found in their claim that If Amelia is a knight then Victoria is a knave. Assume Amelia is a knight. No contradiction is found in their claim that Jacob is not a knave. Assume Jacob is a knight. No contradiction is found in their claim that Victoria is not a knave. Victoria cannot be a knight, because this would contradict the claim of Penelope that If Amelia is a knight then Victoria is a knave. Victoria cannot be a knave, because this would contradict the claim of Jacob that Victoria is not a knave. We have exhausted all possibilities for Victoria, so let us go back and reconsider Jacob. Jacob cannot be a knave, because this would contradict the claim of Amelia that Jacob is not a knave. We have exhausted all possibilities for Jacob, so let us go back and reconsider Amelia. Assume Amelia is a knave. No contradiction is found in their false claim that Jacob is not a knave. Jacob cannot be a knight, because this would contradict the false claim of Amelia that Jacob is not a knave. Assume Jacob is a knave. No contradiction is found in their false claim that Victoria is not a knave. Victoria cannot be a knight, because this would contradict the false claim of Jacob that Victoria is not a knave. Assume Victoria is a knave. No contradiction is found in their false claim that Mia is a knave if and only if Henry is a knave. Henry cannot be a knight, because this would contradict the false claim of Victoria that Mia is a knave if and only if Henry is a knave. Assume Henry is a knave. No contradiction is found in their false claim that Jacob is not a knave.