Dragon Eyes #3
You have arrived at a new village after several days of traveling. As you enter, you pass a sign that says "Welcome to the Village of the Green-Eyed Dragons". Fortunately, you spot a quartet of dragons. Three have green eyes, while the last one is wearing goggles which obscure their eyes. Hesitantly, you approach the dragons.
You ask each dragon "Do green-eyed dragons tell the truth?"
The green-eyed Dragon 1 says "If and only if Dragon 4's eyes are blue."
The green-eyed Dragon 2 says "If and only if Dragon 4's eyes are red."
The green-eyed Dragon 3 says "If and only if Dragon 4's eyes are green."
Dragon 4 says "If and only if my eyes are green."
Do green-eyed dragons lie or tell the truth?
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1 solution
They can do either. Three of the dragons say green-eyed dragons tell the truth if and only if Dragon 2 has a certain eye color.
Therefore, the statements are as follows:
Green-Eyed Dragon 1: Statement is true if Dragon 4 has blue eyes, and false otherwise.
Green-Eyed Dragon 2: Statement is true if Dragon 4 has red eyes, and false otherwise.
Green-Eyed Dragon 3: Statement is true if Dragon 4 has green eyes, and false otherwise.
With this in mind, regardless of which eye color Dragon 4 has, one statement will be true and the other two will be false. In order to avoid a contradiction, the green-eyed dragons must be able to do either.