Addition rules If A, B are any two events then Addition rule P( A or B) = P(A) + P(B) - P(A and B) If A, B disjoint( mutually exclusive, occurring one event precludes theother) P( A or B) = P(A) + P(B) Suppose we pick a card from standard deck of cards. 1. Find the probability to get Heart or Queen. Are these events disjoint (mutually exclusive)? 2. Find the probability to get spade or seven. Are these events disjoint (mutually exclusive)? 3. Find the probability to get face-card or 7. Are these events disjoint (mutually exclusive)? 4. Suppose A, B are any two events with P(A) = 0.75, P(B) = 0.21 and P(A and B) = 0.15. Then find P( A or B). 5. Roll a pair of dice. Find the probability to get odd numbered total or total greater than 9. Are these events disjoint (mutually exclusive)? Show all the possibilities first! probability they w.household dees