Results 1 to 4 of 4

Math Help - Permutations

  1. #1
    Junior Member
    Joined
    Nov 2009
    Posts
    54

    Exclamation Permutations

    Hi

    For this question: how many different arrangements of the letters of the word SERIES are possible if no two vowels are together. I keep on getting 36 instead of 18

    My working out is:

    Consonants can be arranged in 3!/2! ways (X X X) so vowels can be allocated between any of the 4 spaces available i.e. (4 * 3* 2)/2!

    What am I missing out??

    Thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,644
    Thanks
    1596
    Awards
    1
    You are missing that there are two s's.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Nov 2009
    Posts
    54

    Exclamation

    Havent I accounted for that by dividing by 2! for the consonants part?
    Last edited by Sunyata; October 12th 2010 at 05:55 AM.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,644
    Thanks
    1596
    Awards
    1
    I read too quickly. You are correct. I also get 36.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Permutations
    Posted in the Advanced Algebra Forum
    Replies: 12
    Last Post: October 25th 2010, 02:22 AM
  2. Permutations Help
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: March 9th 2010, 07:30 PM
  3. Permutations
    Posted in the Statistics Forum
    Replies: 3
    Last Post: March 11th 2009, 05:39 PM
  4. permutations
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: February 11th 2009, 05:42 PM
  5. Permutations
    Posted in the Statistics Forum
    Replies: 1
    Last Post: September 20th 2008, 11:11 AM

Search Tags


/mathhelpforum @mathhelpforum