Question

"P(A)=0.45 p(B)=? P(A or B)=0.85 p(A/B)=.2 Find B"

Answer 1

Hi,

p(B)=0.49

Explanation:

`p(A)=0.45\\p(A \cup B)=0.85\\p(B)=x\\p(A \cap B)=p(A)+p(B)-p(A \cup B)=0.45+x-0.85\\\\p(A/B)=(p(A \cap B))/(p(A)) =(x-0.4)/(0.45)=0.2\\\\x=0.49\\`