Question 143
On an island there are two types of inhabitants: the knights, who always tell the truth, and the rogues, who always lie. We met on this island a group of four inhabitants who, when questioned about their identity, replied: "There is at least one villain among us." B: "There are at most two knights among us." C: "There are at least three villains among us." D: "There are no knights among us." How many knights are there in this set of four inhabitants?