Question: There is only one pilot on the island. You interview three men, Koik, Lony and Mirna. You also notice that Koik is wearing a cap.
The best way to solve these kinds of questions is to assume that one of the statements is either true or false and thus figure out whether there is consistency in what everyone is saying.
The key here are the statements made by Koik. Since we know that he is wearing a cap, if his first statement is false, then his second statement cannot be true. So his first statement is true and his second statement is false. This implies that Koik is the priest. This makes Lony’s second statement false and so his first statement is true. So Lony is Koik’s son. This makes Mirna’s second statement false and so his first statement is true. So Lony’s father is a pilot. Thus, Koik is the pilot. (Note: Koik is also the priest).