Wednesday, May 22nd

Last update12:59:40 PM GMT

Island of the blue eyed

Write e-mail

There is an island upon which a tribe resides. The residents either have blue eyes or brown eyes. Yet, it is taboo to talk about eye color in any way. Thus, one resident can see the eye colors of all other residents but has no way of discovering his own (there are no reflective surfaces). If a resident does discover his own eye color, then he must commit ritual suicide at 12 noon the following day in the village square for all to witness. Note: Everyone on the island is PERFECTLY LOGICAL.


On this island there are 100 blue eyed people and an unknown number of brown eyed people. Each member sees all the other members each day. One day (day 0), a traveller comes to the island and says aloud for all residents to hear; "On this island, there is at least one person with blue eyes." having said that, she departs. on day 100, all 100 blue eyed people commit suicide simultaneously. Explain the logic behind these suicides.

Remember: There are no mirrors or reflecting surfaces, nothing dumb. It is not a trick question, and the answer is logical. It doesn't depend on tricky wording or anyone lying or guessing, and it doesn't involve people doing something silly like creating a sign language or doing genetics. The traveller is not making eye contact with anyone in particular; she's simply saying "I count at least one blue-eyed person on this island who isn't me."

Share this post

Add comment

Please refrain from using slang or abusive language in the comments.
To avoid waiting for your comment to be published after being reviewed, please log in as a registered user.

Security code

Web Hosting