{"id":752,"date":"2019-03-15T12:52:26","date_gmt":"2019-03-15T16:52:26","guid":{"rendered":"http:\/\/josmfs.net\/?p=752"},"modified":"2019-03-29T07:27:40","modified_gmt":"2019-03-29T11:27:40","slug":"counterfeit-coin-in-base-3","status":"publish","type":"post","link":"https:\/\/josmfs.net\/wordpress\/2019\/03\/15\/counterfeit-coin-in-base-3\/","title":{"rendered":"Counterfeit Coin in Base 3"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-750\" src=\"https:\/\/josmfs.net\/wordpress\/wp-content\/uploads\/2019\/03\/Counterfeit-Coin-Fig.jpg\" alt=\"\" width=\"200\" height=\"187\" \/>Futility Closet presented a nifty method of solving the \u201ccounterfeit coin in 12 coins\u201d problem in a way I had not seen before by mapping the problem into numbers in base 3. It wasn\u2019t immediately clear to me how their solution worked, so I decided to write up my own explanation.<\/p>\n<p>Futility Closet: \u201cYou have 12 coins that appear identical. Eleven have the same weight, but one is either heavier or lighter than the others. How can you identify it, and determine whether it\u2019s heavy or light, in just three weighings in a balance scale? This is a classic puzzle, but in 1992 Washington State University mathematician Calvin T. Long found a solution \u2018that appears little short of magic.\u2019 \u201d<\/p>\n<p>See <a href=\"https:\/\/josmfs.net\/wordpress\/wp-content\/uploads\/2019\/03\/Counterfeit-Coin-in-Base-3-190306.pdf\">Counterfeit Coin in Base 3<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Futility Closet presented a nifty method of solving the \u201ccounterfeit coin in 12 coins\u201d problem in a way I had not seen before by mapping the problem into numbers in base 3. It wasn\u2019t immediately clear to me how their solution worked, so I decided to write up my own explanation. Futility Closet: \u201cYou have [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[89,113,16],"class_list":["post-752","post","type-post","status-publish","format-standard","hentry","category-puzzles-and-problems","tag-base-3","tag-counterfeit-coin","tag-futility-closet"],"_links":{"self":[{"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/posts\/752","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/comments?post=752"}],"version-history":[{"count":2,"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/posts\/752\/revisions"}],"predecessor-version":[{"id":834,"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/posts\/752\/revisions\/834"}],"wp:attachment":[{"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/media?parent=752"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/categories?post=752"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/josmfs.net\/wordpress\/wp-json\/wp\/v2\/tags?post=752"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}