Results 1 to 5 of 5

Math Help - Pre- calc HELP! Combinations

  1. #1
    x83
    x83 is offline
    Newbie
    Joined
    Jul 2013
    From
    washington
    Posts
    2

    Pre- calc HELP! Combinations

    Hi there the question states 2CR=25 I am really new to this so any help would be appreciated it states to solve for R.

    I tried to solve but got no where what i tried was to expand with the formula of nCr and no luck
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Sep 2012
    From
    United States
    Posts
    97
    Thanks
    21

    Re: Pre- calc HELP! Combinations

    2 choose R = 25 is not possible.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    x83
    x83 is offline
    Newbie
    Joined
    Jul 2013
    From
    washington
    Posts
    2

    Re: Pre- calc HELP! Combinations

    Alright

    But if it was, what is the process of solving one of these guys?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,527
    Thanks
    773

    Re: Pre- calc HELP! Combinations

    Quote Originally Posted by x83 View Post
    But if it was, what is the process of solving one of these guys?
    For small values of n, I would search the Pascal's triangle.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,610
    Thanks
    1574
    Awards
    1

    Re: Pre- calc HELP! Combinations

    Quote Originally Posted by x83 View Post
    Hi there the question states 2CR=25 I am really new to this so any help would be appreciated it states to solve for R. I tried to solve but got no where what i tried was to expand with the formula of nCr and no luck
    Using the notation _NC_k unless you are in an advanced mathematics class it is necessary that N\ge k.

    If that is true then _NC_k=M implies \frac{N!}{k!(N-k)!}=M.

    Example: _{N}C_2=105 implies \frac{N(N-1)}{2}=105, solve for N.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. My homework for pre calc class. Its not calc though.
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: January 24th 2013, 06:30 PM
  2. Replies: 0
    Last Post: April 11th 2012, 09:15 AM
  3. A few Pre-Calc problems in my AP Calc summer packet
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: August 30th 2010, 03:40 PM
  4. Replies: 1
    Last Post: January 13th 2010, 11:57 AM
  5. What am I doing? Calc, Pre-calc, Trig, etc...
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: April 23rd 2008, 08:51 AM

Search Tags


/mathhelpforum @mathhelpforum