Question

数学问题！！

Answer 1

求解过程如下：
P（A|B）=P（AB）/P(B)=b;
P(B-A)=P(b)-P(ab)=c;
所以P（ab）=b*pb=b*(C+p(ab));解出来pab=bc/(1-b);
pb=c/(1-b);
P(a+b)=pa+pb-pab带入求解即可；
第三个P（A\b'）=P(Ab')/P(b');
Pb'=1-pb',
pAb'=Pa-PAB;
带入求解就可以得到结果；
满意点个采纳~

Answer 2

Answer 3

P(A)=a

P(A|B)=b
P(B-A)=c
solution:
P(B-A)=c
P(B)-P(A∩B) =c
P(B) = c +P(A∩B)
//
P(A|B)=b
P(A∩B)/P(B)=b
P(A∩B)/[c +P(A∩B)]=b
P(A∩B)=bc +bP(A∩B)
P(A∩B) = bc/(1-b)
//
P(A+B)
= P(A) +P(B)-P(A∩B)
=a + c +P(A∩B) -P(A∩B)
=a+ c
//
P(A|~B)
=P(A∩~B)/P(~B)
=[P(A) -P(A∩B)]/[ 1-P(B)]
=[ a- bc/(1-b) ] /[ 1- c -P(A∩B)]
=[ a- bc/(1-b) ] /[ 1- c -bc/(1-b)]
= (a-ab -bc)/( 1-b- c)