Blue Eyed Monks

In a deserted island 1000 monks live together. Out of these, 100 are blue-eyed, and the rest green-eyed. Blue eyed monks are considered forever cursed, and once a person finds out he has blue eyes, he commits suicide at the next sunbreak. However, monks do not dare to speak about each other's eyes, and nor there are any reflecting surfaces on the island (including the water, which is filthy).

One day, a tourist comes up, and says "at least one of you has blue eyes". Describe what will happen from that point onward. Also, consider what if:

• The tourist says "exactly 100 monks have blue eyes"
• The tourist says "exactly 101 monks have blue eyes"
• The blue eyed monks decide not to commit suicide (the tourist says the first announcement, i.e. "at least one of you has blue eyes"

Solution