Question

Suppose A and B are dependent events. If P(A|B)=0.25 and P(B)=0.8 , what is P(AuB) ?

Answer 1

The Answer is 0.2 hope this helps.

Explanation:

Answer 2

`P(A|B)= \frac{\big{P(A\ \cap\ B)}}{\big{P(B)}}\ \ \ \Rightarrow\ \ \ P(A\ \cap\ B)=P(A|B)\cdot P(B)\\\\ \ \ \ P(A\ \cup\ B)=P(A)+P(B)-P(A\ \cap\ B)\\\\P(A\ \cup\ B)=P(A)+0.8-0.25\cdot0.8=P(A)+0.8-0.2=\\\\=P(A)+0.6`