Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Help with combinations?

Suppose we have 15 bins, numbered 1,...,15 and that we have 15 balls, 8 of them white and 7 of them black.

How many white/black patterns can one make by placing the balls in the bins?

Please explain this to me

2 Answers

Relevance
  • 8 years ago

    If you want 1 ball in each bin:

    C(15,7) = C(15,8) = 15! / (8! * 7!) = 6,435

  • ?
    Lv 7
    8 years ago

    We want (my notation)

    C(15: 7,8) = 15! /(7!8!) = 6435 ways

Still have questions? Get your answers by asking now.