{"id":47,"date":"2010-07-13T15:32:58","date_gmt":"2010-07-13T15:32:58","guid":{"rendered":"http:\/\/mathriddles.williams.edu\/articles\/bridge-over-troubled-students\/"},"modified":"2025-02-10T13:24:23","modified_gmt":"2025-02-10T18:24:23","slug":"bridge-over-troubled-students","status":"publish","type":"post","link":"https:\/\/sites.williams.edu\/mathriddles\/difficulty\/medium\/bridge-over-troubled-students\/","title":{"rendered":"Bridge Over Troubled Students"},"content":{"rendered":"<p>There are four men who want to cross a bridge. They all begin on the same side. You have 17 minutes to get all of them across to the other side. It is night. There is one flashlight. A maximum of two people can cross at one time. Any party who crosses, either one or two people, must have the flashlight with them. The flashlight must be walked back and forth, it cannot be thrown, etc. Each man walks at a different speed. A pair must walk together at the rate of the slower man<\/p>\n<p>Man 1: 1 minute to cross<br \/>\nMan 2: 2 minutes to cross<br \/>\nMan 3: 5 minutes to cross<br \/>\nMan 4: 10 minutes to cross<\/p>\n<p>For example, if Man 1 and Man 4 walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If Man 4 returns with the flashlight, a total of 20 minutes have passed, and you have failed the mission.<\/p>\n<p>Communicated by Jeff Miller.<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-490 size-medium\" src=\"https:\/\/sites.williams.edu\/mathriddles\/files\/2010\/07\/bridge-300x200.jpg\" alt=\"bridge\" width=\"300\" height=\"200\" srcset=\"https:\/\/sites.williams.edu\/mathriddles\/files\/2010\/07\/bridge-300x200.jpg 300w, https:\/\/sites.williams.edu\/mathriddles\/files\/2010\/07\/bridge-450x300.jpg 450w, https:\/\/sites.williams.edu\/mathriddles\/files\/2010\/07\/bridge.jpg 500w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>There are four men who want to cross a bridge. They all begin on the same side. You have 17 minutes to get all of them across to the other side. It is night. There is one flashlight. A maximum of two people can cross at one time. Any party who crosses, either one or&hellip;<\/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":[12,7],"tags":[20],"class_list":["post-47","post","type-post","status-publish","format-standard","hentry","category-combinatorics","category-medium","tag-random"],"acf":[],"_links":{"self":[{"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/posts\/47","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=47"}],"version-history":[{"count":3,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/posts\/47\/revisions"}],"predecessor-version":[{"id":1235,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/posts\/47\/revisions\/1235"}],"wp:attachment":[{"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/media?parent=47"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/categories?post=47"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.williams.edu\/mathriddles\/wp-json\/wp\/v2\/tags?post=47"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}