Studying Probability Theory
摘要：
Chapter 1. How to prove that the r combination from n elements is n!/((n-r)!*r!) ?Answer: we may first find out the permutation of r elements from n: we have n*(n-1)*(n-2)...*(n-r+1) = n!/(n-r)!. In t... 阅读全文
posted @ 2007-07-18 17:55 比尔盖房 阅读(278) 评论(0) 推荐(0) 编辑