{"id":80,"date":"2010-07-13T16:10:31","date_gmt":"2010-07-13T16:10:31","guid":{"rendered":"http:\/\/mathriddles.williams.edu\/?p=80"},"modified":"2025-01-27T09:41:32","modified_gmt":"2025-01-27T14:41:32","slug":"gonna-make-your-brown-eyes-blue","status":"publish","type":"post","link":"https:\/\/sites.williams.edu\/mathriddles\/difficulty\/hard\/gonna-make-your-brown-eyes-blue\/","title":{"rendered":"Gonna Make Your Brown Eyes Blue"},"content":{"rendered":"

1,000 mathematicians live on an island. 600 have brown eyes, and 400 have blue eyes. According to an ancient tradition which is honored by all, if a person ever discovers that he has blue eyes, he will promptly commit suicide the following morning.<\/p>\n

There are no mirrors on the island, and it is considered to be in very poor taste to discuss the subject of eye color. Of course, everyone knows what everyone else’s<\/strong> eye color is.<\/p>\n

One day, a soothsayer passes through the island, and in the presence of the assembled inhabitants solemnly announces: “At least one of you on this island has blue eyes.”<\/p>\n

    \n
  1. What happens?<\/li>\n
  2. What information was divulged by the soothsayer that wasn’t common knowledge before?<\/li>\n
  3. Extra credit: suppose each of the blue-eyed inhabitants had resolved not to commit suicide if they ever discovered their eye color. What happens now?<\/li>\n<\/ol>\n

    Submitted by Steven Phelps.<\/p>\n","protected":false},"excerpt":{"rendered":"

    1,000 mathematicians live on an island. 600 have brown eyes, and 400 have blue eyes. According to an ancient tradition which is honored by all, if a person ever discovers that he has blue eyes, he will promptly commit suicide the following morning. There are no mirrors on the island, and it is considered to…<\/p>\n","protected":false},"author":2861,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[14,6],"tags":[],"class_list":["post-80","post","type-post","status-publish","format-standard","hentry","category-general","category-hard"],"acf":[],"_links":{"self":[{"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/posts\/80","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/users\/2861"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/comments?post=80"}],"version-history":[{"count":1,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/posts\/80\/revisions"}],"predecessor-version":[{"id":1178,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/posts\/80\/revisions\/1178"}],"wp:attachment":[{"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/media?parent=80"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/categories?post=80"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/tags?post=80"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}