Results 1 to 2 of 2

Math Help - help with factorials

  1. #1
    Junior Member
    Joined
    Oct 2007
    Posts
    26

    help with factorials

    A certain office supply store stocks 2 sizes of self-stick notepads, each in 4 colors. The store packs the notepads in packages that contain either 3 notepads of the same size and color or 3 notepads of the same size and of 3 different colors. If the order in which the colors are packed is not considered, how many different packages of the types described above are possible?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,681
    Thanks
    613
    Hello, Simone!

    A certain office supply store stocks 2 sizes of self-stick notepads, each in 4 colors.
    The store packs the notepads in packages that contain
    either 3 notepads of the same size and color
    or 3 notepads of the same size and of 3 different colors.
    If the order in which the colors are packed is not considered,
    how many different packages of the types described above are possible?

    For a type-A package (two sizes, one color), there are:
    . . 2 choices of sizes and 4 choices of colors.
    There are: 2\cdot4 \:=\:8 possible type-A packages.

    For a type-B package (two sizes, three colors), there are:
    . . 2 choices of sizes and {4\choose3} = 4 choices of colors.
    There are: . 2\cdot4\:=\:8 possible type-B packages.

    Therefore, there are: . 8+8\:=\:16 possible packages.

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Factorials 2
    Posted in the Discrete Math Forum
    Replies: 3
    Last Post: November 18th 2009, 12:24 PM
  2. Factorials
    Posted in the Discrete Math Forum
    Replies: 3
    Last Post: November 2nd 2009, 11:35 AM
  3. Factorials
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: May 24th 2009, 09:13 PM
  4. factorials
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 27th 2009, 05:53 PM
  5. factorials
    Posted in the Number Theory Forum
    Replies: 2
    Last Post: June 24th 2006, 06:32 PM

Search Tags


/mathhelpforum @mathhelpforum