设A,B为随机事件,P(A)=0.7,P(A-B)=0.3

问题描述:

设A,B为随机事件,P(A)=0.7,P(A-B)=0.3

求P(AB)

pa-pb=0.3
0.7-pb=0.3
pb=0.4
pa-pb=0.3
p=1
(a-b)=0.3
-b=0.3-a
b=a-0.3
P(ab)=ab