送交者: whoami 于 2010-04-21, 19:18:08:

回答: steven 说的概率相加很有意思。 由 tinaliang 于 2010-04-21, 17:40:04:

• if that is the case, P (A and B) cannot 0, and P (A or B) - steven (27 bytes) 2010-04-21, 20:12:46 (433917)

加跟贴