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New answer posted•a year ago

Set Theory Class 11th

Let S = [1, 2, 3, 4, 5, 6, 9]. Then the number of elements in the set T ${A \subseteq S : A \neq ?$  and the sum of all the elements of A is not a multiple of 3} is____

13 Views|Posted a year ago

Asked by Alok Kumar Singh

Answered by

Alok Kumar Singh | Contributor-Level 10

a year ago

S = {1, 2, 3, 4, 5, 6, 9}

Elements of type 3n -> 3, 6, 9

Type 3n + 1 ->1, 4

3n + 2 -> 2, 5

Number of subset of S containing one element which are not divisible by $3 =^{2} C_{1} +^{2} C_{1} = 4$ number of subset of S containing two numbers whose sum is not divisible $3 =^{3} C_{1} \times^{2} C_{1} +^{3} C_{1} \times^{2} C_{1} +^{2} C_{2} +^{2} C_{2} = 14$ by

Number of subset of S containing 3 elements

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Let S = [1, 2, 3, 4, 5, 6, 9]. Then the number of elements in the set T { A ⊆ S : A ≠ ?  and the sum of all the elements of A is not a multiple of 3} is____

Let S = [1, 2, 3, 4, 5, 6, 9]. Then the number of elements in the set T ${A \subseteq S : A \neq ?$  and the sum of all the elements of A is not a multiple of 3} is____