{"id":261635,"date":"2025-07-20T07:27:01","date_gmt":"2025-07-20T07:27:01","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=261635"},"modified":"2025-07-20T07:27:03","modified_gmt":"2025-07-20T07:27:03","slug":"a-formula-to-be-used-in-linear-permutation-ncr-npr-rcn-prc-2","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/20\/a-formula-to-be-used-in-linear-permutation-ncr-npr-rcn-prc-2\/","title":{"rendered":"A formula to be used in Linear Permutation * nCr nPr rCn pRc"},"content":{"rendered":"\n<p>A formula to be used in Linear Permutation * nCr nPr rCn pRc<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>In combinatorics, we work with several key formulas like linear permutations, combinations, and variations. These formulas help in determining the number of possible arrangements, selections, or groupings from a set of objects. Below is an explanation of how each formula is used and their respective notations:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. <strong>Linear Permutation<\/strong> (also known as <strong>Permutation<\/strong>)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Formula<\/strong>: P(n,r)=n!(n\u2212r)!P(n, r) = \\frac{n!}{(n &#8211; r)!}P(n,r)=(n\u2212r)!n!\u200b<\/li>\n\n\n\n<li><strong>Explanation<\/strong>: A linear permutation represents the number of ways to arrange <strong>r<\/strong> objects from a set of <strong>n<\/strong> distinct objects, where the order matters. The formula takes into account the possible arrangements by dividing the total number of possible objects&#8217; factorials by the factorial of the remaining objects not chosen.<\/li>\n\n\n\n<li><strong>Example<\/strong>: If you have 5 books and want to know how many ways you can arrange 3 of them, you use: P(5,3)=5!(5\u22123)!=5\u00d74\u00d73!2!=60P(5, 3) = \\frac{5!}{(5-3)!} = \\frac{5 \\times 4 \\times 3!}{2!} = 60P(5,3)=(5\u22123)!5!\u200b=2!5\u00d74\u00d73!\u200b=60<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2. <strong>Combinations<\/strong> (also known as <strong>nCr<\/strong>, <strong>Combination<\/strong>)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Formula<\/strong>: C(n,r)=n!r!(n\u2212r)!C(n, r) = \\frac{n!}{r!(n &#8211; r)!}C(n,r)=r!(n\u2212r)!n!\u200b<\/li>\n\n\n\n<li><strong>Explanation<\/strong>: Combinations calculate the number of ways to choose <strong>r<\/strong> objects from a set of <strong>n<\/strong> objects, where the order does not matter. Unlike permutations, the order of selection does not affect the outcome, so we divide by the factorial of the number of selections.<\/li>\n\n\n\n<li><strong>Example<\/strong>: If you want to select 3 books from a set of 5, regardless of order, the calculation is: C(5,3)=5!3!(5\u22123)!=5\u00d74\u00d73!3!\u00d72!=10C(5, 3) = \\frac{5!}{3!(5 &#8211; 3)!} = \\frac{5 \\times 4 \\times 3!}{3! \\times 2!} = 10C(5,3)=3!(5\u22123)!5!\u200b=3!\u00d72!5\u00d74\u00d73!\u200b=10<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. <strong>nPr<\/strong> (Permutation of <strong>n<\/strong> objects taken <strong>r<\/strong> at a time)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Formula<\/strong>: P(n,r)=n!(n\u2212r)!P(n, r) = \\frac{n!}{(n &#8211; r)!}P(n,r)=(n\u2212r)!n!\u200b<\/li>\n\n\n\n<li><strong>Explanation<\/strong>: This is just another way of representing the permutation formula where the number of arrangements of <strong>r<\/strong> objects taken from <strong>n<\/strong> objects is calculated. This is identical to the linear permutation formula.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4. <strong>rCn<\/strong> (Combination of <strong>r<\/strong> objects chosen from a set of <strong>n<\/strong>)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Formula<\/strong>: This is the same as the combination formula: C(n,r)=n!r!(n\u2212r)!C(n, r) = \\frac{n!}{r!(n &#8211; r)!}C(n,r)=r!(n\u2212r)!n!\u200b<\/li>\n\n\n\n<li><strong>Explanation<\/strong>: It denotes the number of ways to choose <strong>r<\/strong> objects from <strong>n<\/strong>, which is typically referred to as <strong>nCr<\/strong> in combinatorics.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Summary:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Linear permutation<\/strong> is used when <strong>order matters<\/strong>: P(n,r)=n!(n\u2212r)!P(n, r) = \\frac{n!}{(n &#8211; r)!}P(n,r)=(n\u2212r)!n!\u200b<\/li>\n\n\n\n<li><strong>Combinations<\/strong> are used when <strong>order does not matter<\/strong>: C(n,r)=n!r!(n\u2212r)!C(n, r) = \\frac{n!}{r!(n &#8211; r)!}C(n,r)=r!(n\u2212r)!n!\u200b<\/li>\n<\/ul>\n\n\n\n<p>Each of these formulas has real-world applications like selecting teams, arranging items, or scheduling events.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/07\/learnexams-banner6-1170.jpeg\" alt=\"\" class=\"wp-image-261638\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>A formula to be used in Linear Permutation * nCr nPr rCn pRc The Correct Answer and Explanation is: In combinatorics, we work with several key formulas like linear permutations, combinations, and variations. These formulas help in determining the number of possible arrangements, selections, or groupings from a set of objects. Below is an explanation [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-261635","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/261635","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=261635"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/261635\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=261635"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=261635"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=261635"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}