- #1
zeion
- 466
- 1
Homework Statement
I don't understand the equation for drawing with replacement and considering results to be unordered.
So with replacement and no attention to order all we see is the number of each color drawn. So this is represented by o's and x's where o's is the number of that color drawn and x is a separator for the next color.
If # of different colors is n and # of draws is k then # of o's is k and # of x's is n - 1.
So now I need to find all the possible permutation of this set of x's and o's.
I don't understand why it is k + n - 1 choose n - 1 (?)
(k + n - 1)! / (n - 1)! (k + n - 1 - (n - 1))! (?)