CombinatoricsDifficulty 2.0JuniorFind the answerUnited Kingdom
There are four people, some of whom always tell the truth. The others always lie. The first person said, "An odd number of us always tell the truth". The second person said, "An even number of us always tell the truth". The third person said, "A prime number of us always tell the truth". The fourth person said, "A square number of us always tell the truth". How many of these four people were telling the truth?
(A) 0 (B) 1 (C) 2 (D) 3 (E) 4
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