There is an island in the middle of the ocean. On this island there are 100 people with green eyes, 100 people with blue eyes, and one seer with brown eyes.
The people on this island are perfectly logical. They also know that the other people on the island are perfectly logical and can make logical conclusions based on what a perfectly logical person would conclude themselves.
They have a get together every day, where every person on the island gets to see every other person. There are no mirrors on the island and the water is too murky to reflect anything. In short they can't ever see their own eye color.
There's a rule for leaving the island. Once ALL of the people of a particular eye color can identify their own eye color (Ie: All 100 people who have blue eyes can say with perfect knowledge that they have blue eyes) they can leave.
Everybody is mute except for the seer.
One day in the middle of the summer the seer opens her eyes and says "I see a person with blue eyes"
When can the first group of people leave? What color are their eyes?
The people on this island are perfectly logical. They also know that the other people on the island are perfectly logical and can make logical conclusions based on what a perfectly logical person would conclude themselves.
They have a get together every day, where every person on the island gets to see every other person. There are no mirrors on the island and the water is too murky to reflect anything. In short they can't ever see their own eye color.
There's a rule for leaving the island. Once ALL of the people of a particular eye color can identify their own eye color (Ie: All 100 people who have blue eyes can say with perfect knowledge that they have blue eyes) they can leave.
Everybody is mute except for the seer.
One day in the middle of the summer the seer opens her eyes and says "I see a person with blue eyes"
When can the first group of people leave? What color are their eyes?
