{"id":11557,"date":"2026-10-01T12:15:29","date_gmt":"2026-10-01T06:45:29","guid":{"rendered":"https:\/\/internshala.com\/competitions\/?p=11557"},"modified":"2026-10-01T12:15:29","modified_gmt":"2026-10-01T06:45:29","slug":"combinatorics-open-2026","status":"publish","type":"post","link":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/","title":{"rendered":"Combinatorics Open 2026"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">\ud83d\udccc About the Event<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Combinatorics Open 2026 is a free, online international mathematics competition designed for pre-university students from anywhere in the world. The competition focuses on combinatorial thinking through problems involving counting, probability, graph theory, invariants, recursion, games and other areas of discrete mathematics. Participants will solve 20 short-answer problems individually within a 90-minute session during a 48-hour worldwide competition window.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u2139\ufe0f Event Details<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Organizer:<\/strong> Combinatorics Open<\/li>\n\n\n\n<li><strong>Type:<\/strong> International Mathematics Competition<\/li>\n\n\n\n<li><strong>Mode:<\/strong> Online<\/li>\n\n\n\n<li><strong>Participation:<\/strong> Individual<\/li>\n\n\n\n<li><strong>Eligibility:<\/strong> Pre-university students worldwide who have not completed secondary school<\/li>\n\n\n\n<li><strong>Competition Format:<\/strong> 20 short-answer problems<\/li>\n\n\n\n<li><strong>Duration:<\/strong> 90 minutes<\/li>\n\n\n\n<li><strong>Competition Window:<\/strong> 48 hours<\/li>\n\n\n\n<li><strong>Language:<\/strong> English<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83d\udcc5 Important Dates<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Registration Opens:<\/strong> 12 September 2026<\/li>\n\n\n\n<li><strong>Sample Problems Published:<\/strong> 21 September 2026<\/li>\n\n\n\n<li><strong>Problem of the Week Begins:<\/strong> 1 October 2026<\/li>\n\n\n\n<li><strong>Registration Deadline:<\/strong> 13 November 2026, <strong>5:30 PM IST<\/strong><\/li>\n\n\n\n<li><strong>Competition Starts:<\/strong> 14 November 2026, <strong>5:30 AM IST<\/strong><\/li>\n\n\n\n<li><strong>Competition Ends:<\/strong> 16 November 2026, <strong>5:29 AM IST<\/strong><\/li>\n\n\n\n<li><strong>Problems &amp; Solutions Published:<\/strong> 17 November 2026<\/li>\n\n\n\n<li><strong>Preliminary Results:<\/strong> 19 November 2026<\/li>\n\n\n\n<li><strong>Final Results:<\/strong> 24 November 2026<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83c\udfaf Eligibility&amp; Rules <\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ties are resolved by comparing performance on the hardest problems, beginning with Problem 20.<\/li>\n\n\n\n<li>Open to students who have not completed secondary school, regardless of country or grade.<\/li>\n\n\n\n<li>Students in Grade 10 or below (or equivalent) are eligible for the Junior Ranking.<\/li>\n\n\n\n<li>Dual-enrolled secondary school students are eligible.<\/li>\n\n\n\n<li>Participation is individual; no teams.<\/li>\n\n\n\n<li>Participants must solve 20 short-answer mathematics problems in 90 minutes.<\/li>\n\n\n\n<li>Calculators, coding, online searches, published references, and outside assistance are not allowed.<\/li>\n\n\n\n<li>Participants must work independently throughout the contest.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83c\udfc6 Benefits<strong> for the Participants<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Gold, Silver and Bronze performance designations<\/li>\n\n\n\n<li>Separate Junior Ranking for Grade 10 and below, or equivalent<\/li>\n\n\n\n<li>Country Top Scorer recognition for countries with at least five official participants<\/li>\n\n\n\n<li>Digital certificate for all participants<\/li>\n\n\n\n<li>Official problems, solutions and results will be made publicly available after the competition<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\ud83d\udccc About the Event Combinatorics Open 2026 is a free, online international mathematics competition designed for pre-university students from anywhere in the world. The competition focuses on combinatorial thinking through<\/p>\n","protected":false},"author":13,"featured_media":11563,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[2],"tags":[],"class_list":["post-11557","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-contests"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v26.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Combinatorics Open 2026: Eligibility &amp; Registration<\/title>\n<meta name=\"description\" content=\"Combinatorics Open 2026 is a free online mathematics competition for pre-university students worldwide. Register by 13 November 2026 to participate.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Combinatorics Open 2026: Eligibility &amp; Registration\" \/>\n<meta property=\"og:description\" content=\"Combinatorics Open 2026 is a free online mathematics competition for pre-university students worldwide. Register by 13 November 2026 to participate.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/\" \/>\n<meta property=\"og:site_name\" content=\"Internshala Competitions\" \/>\n<meta property=\"article:published_time\" content=\"2026-10-01T06:45:29+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png\" \/>\n\t<meta property=\"og:image:width\" content=\"358\" \/>\n\t<meta property=\"og:image:height\" content=\"200\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"Jisha\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Jisha\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/\"},\"author\":{\"name\":\"Jisha\",\"@id\":\"https:\/\/internshala.com\/competitions\/#\/schema\/person\/1470721b4970a3f75f84c8c99627f6dd\"},\"headline\":\"Combinatorics Open 2026\",\"datePublished\":\"2026-10-01T06:45:29+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/\"},\"wordCount\":266,\"publisher\":{\"@id\":\"https:\/\/internshala.com\/competitions\/#organization\"},\"image\":{\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png\",\"articleSection\":[\"Contests\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/\",\"url\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/\",\"name\":\"Combinatorics Open 2026: Eligibility & Registration\",\"isPartOf\":{\"@id\":\"https:\/\/internshala.com\/competitions\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png\",\"datePublished\":\"2026-10-01T06:45:29+00:00\",\"description\":\"Combinatorics Open 2026 is a free online mathematics competition for pre-university students worldwide. Register by 13 November 2026 to participate.\",\"breadcrumb\":{\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage\",\"url\":\"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png\",\"contentUrl\":\"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png\",\"width\":358,\"height\":200,\"caption\":\"combinatorics (1)\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/internshala.com\/competitions\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Contests\",\"item\":\"https:\/\/internshala.com\/competitions\/contests\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Combinatorics Open 2026\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/internshala.com\/competitions\/#website\",\"url\":\"https:\/\/internshala.com\/competitions\/\",\"name\":\"Internshala Competitions\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/internshala.com\/competitions\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/internshala.com\/competitions\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/internshala.com\/competitions\/#organization\",\"name\":\"Internshala Competitions\",\"url\":\"https:\/\/internshala.com\/competitions\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/internshala.com\/competitions\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/04\/13050601\/header_logo.png\",\"contentUrl\":\"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/04\/13050601\/header_logo.png\",\"width\":300,\"height\":80,\"caption\":\"Internshala Competitions\"},\"image\":{\"@id\":\"https:\/\/internshala.com\/competitions\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/internshala.com\/competitions\/#\/schema\/person\/1470721b4970a3f75f84c8c99627f6dd\",\"name\":\"Jisha\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/internshala.com\/competitions\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/515ee65a9eafbf28e39058da9ac859e3fce83bce97fc144b7c55f717d880bd6f?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/515ee65a9eafbf28e39058da9ac859e3fce83bce97fc144b7c55f717d880bd6f?s=96&d=mm&r=g\",\"caption\":\"Jisha\"},\"url\":\"https:\/\/internshala.com\/competitions\/author\/jisha\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Combinatorics Open 2026: Eligibility & Registration","description":"Combinatorics Open 2026 is a free online mathematics competition for pre-university students worldwide. Register by 13 November 2026 to participate.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/","og_locale":"en_US","og_type":"article","og_title":"Combinatorics Open 2026: Eligibility & Registration","og_description":"Combinatorics Open 2026 is a free online mathematics competition for pre-university students worldwide. Register by 13 November 2026 to participate.","og_url":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/","og_site_name":"Internshala Competitions","article_published_time":"2026-10-01T06:45:29+00:00","og_image":[{"width":358,"height":200,"url":"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png","type":"image\/png"}],"author":"Jisha","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Jisha","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#article","isPartOf":{"@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/"},"author":{"name":"Jisha","@id":"https:\/\/internshala.com\/competitions\/#\/schema\/person\/1470721b4970a3f75f84c8c99627f6dd"},"headline":"Combinatorics Open 2026","datePublished":"2026-10-01T06:45:29+00:00","mainEntityOfPage":{"@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/"},"wordCount":266,"publisher":{"@id":"https:\/\/internshala.com\/competitions\/#organization"},"image":{"@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage"},"thumbnailUrl":"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png","articleSection":["Contests"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/","url":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/","name":"Combinatorics Open 2026: Eligibility & Registration","isPartOf":{"@id":"https:\/\/internshala.com\/competitions\/#website"},"primaryImageOfPage":{"@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage"},"image":{"@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage"},"thumbnailUrl":"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png","datePublished":"2026-10-01T06:45:29+00:00","description":"Combinatorics Open 2026 is a free online mathematics competition for pre-university students worldwide. Register by 13 November 2026 to participate.","breadcrumb":{"@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#primaryimage","url":"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png","contentUrl":"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/10\/01121211\/combinatorics-1.png","width":358,"height":200,"caption":"combinatorics (1)"},{"@type":"BreadcrumbList","@id":"https:\/\/internshala.com\/competitions\/combinatorics-open-2026\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/internshala.com\/competitions\/"},{"@type":"ListItem","position":2,"name":"Contests","item":"https:\/\/internshala.com\/competitions\/contests\/"},{"@type":"ListItem","position":3,"name":"Combinatorics Open 2026"}]},{"@type":"WebSite","@id":"https:\/\/internshala.com\/competitions\/#website","url":"https:\/\/internshala.com\/competitions\/","name":"Internshala Competitions","description":"","publisher":{"@id":"https:\/\/internshala.com\/competitions\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/internshala.com\/competitions\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/internshala.com\/competitions\/#organization","name":"Internshala Competitions","url":"https:\/\/internshala.com\/competitions\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/internshala.com\/competitions\/#\/schema\/logo\/image\/","url":"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/04\/13050601\/header_logo.png","contentUrl":"https:\/\/internshala-competitions.s3.ap-south-1.amazonaws.com\/competitions\/wp-content\/uploads\/2026\/04\/13050601\/header_logo.png","width":300,"height":80,"caption":"Internshala Competitions"},"image":{"@id":"https:\/\/internshala.com\/competitions\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/internshala.com\/competitions\/#\/schema\/person\/1470721b4970a3f75f84c8c99627f6dd","name":"Jisha","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/internshala.com\/competitions\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/515ee65a9eafbf28e39058da9ac859e3fce83bce97fc144b7c55f717d880bd6f?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/515ee65a9eafbf28e39058da9ac859e3fce83bce97fc144b7c55f717d880bd6f?s=96&d=mm&r=g","caption":"Jisha"},"url":"https:\/\/internshala.com\/competitions\/author\/jisha\/"}]}},"_links":{"self":[{"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/posts\/11557","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/comments?post=11557"}],"version-history":[{"count":4,"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/posts\/11557\/revisions"}],"predecessor-version":[{"id":11562,"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/posts\/11557\/revisions\/11562"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/media\/11563"}],"wp:attachment":[{"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/media?parent=11557"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/categories?post=11557"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/internshala.com\/competitions\/wp-json\/wp\/v2\/tags?post=11557"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}