{"id":14298,"date":"2016-02-11T18:33:30","date_gmt":"2016-02-11T18:33:30","guid":{"rendered":"http:\/\/www.oracletutoring.ca\/blog\/?p=14298"},"modified":"2016-02-11T18:33:30","modified_gmt":"2016-02-11T18:33:30","slug":"math-combinations-a-question-from-a-text","status":"publish","type":"post","link":"https:\/\/www.oracletutoring.ca\/blog\/math-combinations-a-question-from-a-text\/","title":{"rendered":"Math: combinations: a question from a text"},"content":{"rendered":"

The tutor offers a solution to a textbook question about counting.<\/h1>\n

On page 47 of my text Discrete and Combinatorial Mathematics<\/u> (Grimaldi) is a question:<\/p>\n

If you want to select three distinct letters from the alphabet , arranged in alphabetical order, how many ways can it be done?<\/em><\/p>\n

The answer I’m offering is 26C3. Here’s my reasoning: let’s imagine you select P,Q, and A. They’re not in alphabetical order, but as a combination, the order doesn’t matter. Therefore, I can rearrange them to A,P,Q, and it’s still the same combination.<\/p>\n

There are 26C3 combinations of three distinct letters from the alphabet. Since combinations are careless of order, you can arrange each combination to alphabetical order:)<\/p>\n

Source:<\/p>\n

Grimaldi, Ralph P. Discrete and Combinatorial Mathematics<\/u>. Don Mills: Addison-
  Wesley, 1994.<\/p>\n

Jack of Oracle Tutoring by Jack and Diane,<\/a> Campbell River, BC.<\/p>\n","protected":false},"excerpt":{"rendered":"

The tutor offers a solution to a textbook question about counting. On page 47 of my text Discrete and Combinatorial Mathematics (Grimaldi) is a question: If you want to select three distinct letters from the alphabet , arranged in alphabetical …<\/p>\n

Math: combinations: a question from a text<\/span> Read More »<\/a><\/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":[1424,1423,83],"class_list":["post-14298","post","type-post","status-publish","format-standard","hentry","category-math","tag-combinations","tag-combinatorics","tag-counting"],"_links":{"self":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts\/14298","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/comments?post=14298"}],"version-history":[{"count":9,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts\/14298\/revisions"}],"predecessor-version":[{"id":14307,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/posts\/14298\/revisions\/14307"}],"wp:attachment":[{"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/media?parent=14298"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/categories?post=14298"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.oracletutoring.ca\/blog\/wp-json\/wp\/v2\/tags?post=14298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}