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____

0 4 Views | Posted 2 months ago
Asked by Shiksha User

  • 1 Answer

  • A

    Answered by

    alok kumar singh | Contributor-Level 10

    2 months 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 × 2 C 1 + 3 C 1 × 2 C 1 + 2 C 2 + 2 C 2 = 1 4 by

    Number of subset of S containing 3 elements whose sum is not divisible by

    Number of subset containing 4 elements whose sum is not divisible by 3

    Number of subset of S containing 6 elements = 4

    Hence total subset = 80

     

Get authentic answers from experts, students and alumni that you won't find anywhere else

Sign Up on Shiksha

On Shiksha, get access to

  • 65k Colleges
  • 1.2k Exams
  • 687k Reviews
  • 1800k Answers

Learn more about...

Share Your College Life Experience

Didn't find the answer you were looking for?

Search from Shiksha's 1 lakh+ Topics

or

Ask Current Students, Alumni & our Experts

×

This website uses Cookies and related technologies for the site to function correctly and securely, improve & personalise your browsing experience, analyse traffic, and support our marketing efforts and serve the Core Purpose. By continuing to browse the site, you agree to Privacy Policy and Cookie Policy.

Need guidance on career and education? Ask our experts

Characters 0/140

The Answer must contain atleast 20 characters.

Add more details

Characters 0/300

The Answer must contain atleast 20 characters.

Keep it short & simple. Type complete word. Avoid abusive language. Next

Your Question

Edit

Add relevant tags to get quick responses. Cancel Post