Events A and B are such that P(A) = 0.2, P(B) = 0.3. If event A happens then it is disjoint from the event B. What is the probability of "either A or B or both"?

Part a

What is the probability of "either A or B"? provide some justification for your answer.

Part b

Recall that P(A|B) P(B) = p(A and B). The statement that "P(A|B) = P(B|A)" whenever A and B are independent events" is (Circle: TRUE/FALSE). Justify your answer