Results 1 to 2 of 2

Math Help - Solutions in non negative and positive intergers

  1. #1
    Junior Member
    Joined
    Jan 2010
    Posts
    28

    Solutions in non negative and positive intergers

    Hi, I've been going over some problems that I don't have answers too and just need some verification that what im doing is right!!

    Find the number of solutions in a) non negative and b) positive intergers for a+b+c+d=12

    For a) I have \binom{12+4-1}{4-1} = \binom{15}{3} = 455
    and b) \binom{8+4-1}{4-1} = \binom{11}{3} = 165

    I think/hope that is right but I've got no way of checking!! Cheers for any help!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,381
    Thanks
    1474
    Awards
    1
    Quote Originally Posted by shmounal View Post
    Find the number of solutions in a) non negative and b) positive intergers for a+b+c+d=12

    For a) I have \binom{12+4-1}{4-1} = \binom{15}{3} = 455
    and b) \binom{8+4-1}{4-1} = \binom{11}{3} = 165
    Both are correct.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Positive or Negative Infinity?
    Posted in the Calculus Forum
    Replies: 7
    Last Post: February 27th 2011, 05:44 AM
  2. when the f(x) positive, negative, or zero
    Posted in the Calculus Forum
    Replies: 1
    Last Post: April 19th 2009, 04:34 PM
  3. Negative/positive Roots?
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 29th 2009, 11:29 AM
  4. Positive and Negative Integers
    Posted in the Algebra Forum
    Replies: 1
    Last Post: July 2nd 2007, 06:32 PM

Search Tags


/mathhelpforum @mathhelpforum