题目内容：

what is the answer of this probality question?
1.Suppose that visitors to a web page can click one of two buttons:“buy” or “cancel”.Visitors make decisions independently and for each visitor:
P[“buy”] = 0.3
P[“cancel”] = 0.7
(a) If 6 people visit the web page,what is the probability that exactly two of them buy?
(b) If 6 people visit the web page,what is the probability that at least two of them buy?
(c) If 6 people visit the web page,what is the probability that only the last person buys?

优质解答

a) 0.3*0.3*0.7*0.7*0.7*0.7*6*5/2=0.324135
b)1-0.7^6-6*0.3*0.7^5=0.579825
C) 0.3