1. 12.4 Find Probabilities of Disjoint and Overlapping Events
Mrs. vazquez
Geometry

2. (S.cp.)1, 4, 5, 7, 9, (s.md)6, 7 Essential Question: How are many
Objective:
Students will be able to find probabilities of compound events.

3. definitions compound event: the union or intersection of two events
overlapping events:
when two events have 1+ outcomes in common
disjoint event: (mutually exclusive events) when two events have no common outcome

4. probability formulas
P(A or B) = P(A) + P(B) - P(A & B)
P(A or B) = P(A) + P(B)
A card is randomly selected from a standard deck of 52 cards. Find the probability of the given event.
Selecting an ace or an eight
Selecting a 10 or a diamond

5. solve
Out of 200 students in a senior class, 64 seniors are either in band or on honor roll. 32 seniors are in band & 51 seniors are on the honor roll. What is the probability that a randomly selected senior is both in band & on the honor roll?

6. complement of an event complement:
(Ā) all outcomes that are not in event A
Ā: “A bar”
P(Ā) = 1 - P(A)

7. solve
A restaurant gives a free fortune cookie to every guest. The restaurant claims there are 100 different hidden messages inside the cookies. What is the probability that a group of 5 people will receive at least 2 fortune cookies with the same message?
How does the answer change if there are 500 different messages?