1. Probability

2. The likelihood that a given event will occur.
Probability
The likelihood that a given event will occur.
Theoretical Probability: The number of ways that an event can occur, divided by the total number of outcomes in the sample space.

3. Compound Events
combines two or more events, using the word and or the word or.

4. AND
Means you MULTIPLY

5. Independent Events (with replacement)
Two events A and B, are independent if the fact that A occurs does not affect the probability of B occurring.
Probability of A and B occurring:

6. Example
A coin is tossed and a 6-sided die is rolled. What is the probability of landing on heads and rolling a 3?

7. YOU Try
You choose a card from a standard deck, put it back, then choose another card.What is the probability that both cards will be red?

8. Dependent Events (without replacement)
Two events A and B, are dependent if the fact that A occurs affects the probability of B occurring.
Not replacing will cause you to subtract from the denominator (and sometimes from the numerator).

9. Example
A jar contains 3 red, 5 green, 2 blue and 6 yellow marbles. A marble is chosen at random from the jar.
A second marble is chosen without replacing the first one.
Find P(a green and a yellow marble).

10. YOU Try
You are picking teams to play basketball in your P.E. class. There are 10 boys and 7 girls.
What is the probability that the first two people you pick are both girls?

11. Find the probability of….
*In a standard deck of cards, the
*In a standard deck of cards, the probability of getting 2 Aces if you don’t replace the first one.
*If you are buying 2 cars, and there are 5 blue, 2 red, 7 white, 3 silver, what is the probability of you buying both cars in blue?
*If you roll 2 dice, the
*If you flip a penny and a quarter, the

12. OR
Means you ADD

13. Mutually Exclusive two or more events cannot occur at the same time
They have no common outcomes.

14. For Mutually Exclusive Events:
Find the probability of each and ADD:

15. Example
Using a standard deck of 52 cards: Find the

16. Example When rolling two dice, what is P(sum of 4 sum of 5)? 1 2 3 4 56 7 8 9 10 11 12

17. Overlapping events have at least one common outcome.
You will have to SUBTRACT out the overlapping amount

18. Example
Find the P(King Clubs)?

19. Example
Find the P(female or FL) out of the committee members listed in the table.
Fem
Male FL 8 4 AL 6 3 GA 7

20. How do we do it??
Find the P(Red Queen or King).

21. How do we do it??
Susan picks a card, and then picks another card out of a deck without replacing the first. What is the probability they are both Aces?

22. How do we do it??
Find the P(Spades or Face Card).