{"id":9522,"date":"2022-01-15T23:41:49","date_gmt":"2022-01-15T18:11:49","guid":{"rendered":"https:\/\/mathemerize.com\/?p=9522"},"modified":"2022-01-15T23:41:52","modified_gmt":"2022-01-15T18:11:52","slug":"prove-that-the-total-number-of-subsets-of-a-finite-set-containing-n-elements-is-2n","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/prove-that-the-total-number-of-subsets-of-a-finite-set-containing-n-elements-is-2n\/","title":{"rendered":"Prove that the total number of subsets of a finite set containing n elements is \\(2^n\\)."},"content":{"rendered":"
Let A be a finite set containing n elements. Let 0 \\(\\le\\) r \\(\\le\\) n.<\/p>\n
Consider those subsets of A that have r elements each. We know that the number of ways in which r elements can be chosen out of n elements is \\(^nC_r\\).<\/p>\n
Therefore, the number of subsets of A having r elements each is \\(^nC_r\\).<\/p>\n
Hence, the total number of subsets of A<\/p>\n
= \\(^nC_0\\) + \\(^nC_1\\) + \\(^nC_2\\) + …. + \\(^nC_n\\) = \\((1 + 1)^n\\) = \\(2^n\\).<\/p>\n
[ Using binomial theorem ]<\/p>\n","protected":false},"excerpt":{"rendered":"
Solution : Let A be a finite set containing n elements. Let 0 \\(\\le\\) r \\(\\le\\) n. Consider those subsets of A that have r elements each. We know that the number of ways in which r elements can be chosen out of n elements is \\(^nC_r\\). Therefore, the number of subsets of A having …<\/p>\n