Results 1 to 6 of 6
Like Tree1Thanks
  • 1 Post By emakarov

Math Help - tree

  1. #1
    Senior Member
    Joined
    Feb 2010
    Posts
    456
    Thanks
    34

    tree

    a tree has two vertices of degree 2 one vertex of degree 3 and three vertices of degree 4.how many vertices of degree 1 are there

    i am getting 0 is it correct
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,545
    Thanks
    780

    Re: tree

    Does the problem statement mean that there are no vertices with degrees higher than 4? Also, don't all leaves have degree 1?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Feb 2010
    Posts
    456
    Thanks
    34

    Re: tree

    i am confused i had seen a formula

    d1+d2+...dn=2n-2 where d is degree and n number of vertices
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,545
    Thanks
    780

    Re: tree

    Quote Originally Posted by prasum View Post
    i had seen a formula

    d1+d2+...dn=2n-2 where d is degree and n number of vertices
    And how does it imply that there are no vertices of degree 1?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Senior Member
    Joined
    Feb 2010
    Posts
    456
    Thanks
    34

    Re: tree

    i found the total vertices as 6+m where m is the no of vertices for degree 1
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,545
    Thanks
    780

    Re: tree

    Quote Originally Posted by prasum View Post
    i found the total vertices as 6+m where m is the no of vertices for degree 1
    Yes, and the sum of degrees is 2 * 2 + 1 * 3 + 3 * 4 + m = 19 + m. Now solve the equation 19 + m = 2(6 + m) - 2.
    Thanks from prasum
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. tree
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: April 25th 2011, 06:56 AM
  2. 2 colourable tree
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: October 12th 2010, 06:18 PM
  3. graph + tree
    Posted in the Discrete Math Forum
    Replies: 3
    Last Post: July 4th 2010, 11:27 PM
  4. game tree
    Posted in the Discrete Math Forum
    Replies: 0
    Last Post: January 28th 2010, 09:30 AM
  5. Tree with MOD proof
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: April 12th 2009, 12:50 PM

Search Tags


/mathhelpforum @mathhelpforum