On the isle of Uauau the natives speak the truth on one day and lie on the next. On his or her “truth-day”, the man or woman will always speak the truth, and on their “lie-days” they will always lie. As a further complication, their truth days and lie-days are not synchronized, what is a truth day for one of them can be a lie day for his neighbor, father, brother or friend.

**1) Today is a truth-day for me**^{*/*****}

You meet a native who says: “Today is my truth day”. Can you conclude if he has a truth-day or not?

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**2) Yesterday**^{*/*****}

On Friday you meet a native who tells you: “Thursday is one of my lie-days”. Can you conclude if the native is speaking the truth or not?

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**3) Different truth-days**^{**/*****}

You meet two natives. One of them tells you:

“My friend and I have different Truth-days. Today is my friend’s lie-day.”

Does at least one of them have a lie-day?

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**4) Friday(1)**^{***/*****}

You meet two natives, let’s call them A and B as their real names are hard to pronounce. A says:

(1) My friend and I have the same truth-days.

(2) Last Friday my friend had a lie-day.

Does A speak the truth?

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**5) Friday(2)**^{***/*****}

You meet two natives on a Friday. For a change, let’s call them A and B, as their names are hard to remember. A says:

Yesterday I would have said that Friday is B’s truth-day.

Does B have a truth-day today?

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