Results 1 to 3 of 3

Math Help - Counting problem

  1. #1
    Newbie
    Joined
    Apr 2013
    From
    London
    Posts
    6

    Counting problem

    Janice is choosing some CDs from her collection to take to a party. She owns 10 jazz CDs, 15 pop CDs and 8 hip hop CDs.
    Fred is bringing 6 pop CDs to the party. Janice knows that Fred owns 4 of the pop CDs that are in her collection. How many pop CDs must she bring to the party to ensure that between them they have brought at least 9distinct pop CDs?

    I thought about the pigeonhole principle,but it turn out the answer is 20766240. Can someone pls help
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Mar 2013
    From
    BC, Canada
    Posts
    100
    Thanks
    16

    Re: Counting problem

    Worst case scenario is that Fred brings all 4 pop CDs that Janice owns. If Janice brings 11 of her pop CDs, and worst case she picks all 4 as well, then there will be a total of 8 CDs that are duplicate, and 9 that will be distinct (2 from Fred and 7 from Janice). No idea where your final answer came from.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2013
    From
    London
    Posts
    6

    Re: Counting problem

    Quote Originally Posted by majamin View Post
    Worst case scenario is that Fred brings all 4 pop CDs that Janice owns. If Janice brings 11 of her pop CDs, and worst case she picks all 4 as well, then there will be a total of 8 CDs that are duplicate, and 9 that will be distinct (2 from Fred and 7 from Janice). No idea where your final answer came from.
    That is exactly how I worked out. I'm currently waiting an email from my teacher. If the answer is actually as she claims it to be, then I shall let you know ASAP
    Thanks anyway
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Counting problem!
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: October 8th 2009, 09:31 AM
  2. Counting Problem
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: May 10th 2009, 10:06 AM
  3. Replies: 3
    Last Post: April 13th 2009, 06:42 PM
  4. counting problem
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: March 30th 2009, 06:06 PM
  5. Set Counting Problem
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: January 3rd 2009, 06:49 PM

Search Tags


/mathhelpforum @mathhelpforum