1. Warm Up
One card is selected at random from a standard deck of 52 playing cards. What is the probability that the card is either a club or an ace?

2. Complement of an Event
The Complement of an event A is the collection of all outcomes in the sample space that are not in A. If the probability of A is P(A), then the probability of the complement A’ is given by P(A’) = 1 – P(A).

4. 14.5 –Probability of Dependent & Independent Events
Determining the difference between independent and dependent event is the first step in finding probability…
Probability of Two Independent Events
P(A and B) = P(A) * P(B)
Probability of Two Dependent Events
P(A and B) = P(A) * P(B after A)

5. Ex. 1
Find the probability of getting a sum of 7 on the first toss of two dice and a sum of 4 on the second toss.
1 72

6. Ex. 2
A shelf in an English class contains 3 red cover dictionaries and 4 blue. One student takes dictionary looks up a word and puts it back on the shelf. A second student does the same thing. What is the probability that both students used a blue dictionary?
What if the first student did not return the book?
16 49
2 7

7. Ex. 3
Frank has 6 gray socks and 4 blue socks in a drawer. One dark morning he randomly pulls out 2 socks. What is the probability that he will select a pair of gray socks?
1 3

8. Determine if each event is independent or dependent
Determine if each event is independent or dependent. Then find the probability.
There are 2 glasses of root beer and 4 glasses of Sprite on the counter. Dave drinks two of them at random. What is the probability he drank 2 glasses of Sprite?
2 5 8

9. A bowl contains 5 oranges and 4 apples
A bowl contains 5 oranges and 4 apples. Ann randomly selects one, puts it back, and then selects another. What is the probability that both selections were oranges?
A green die and a red die are tossed. What is the probability that a 4 shows on the green die and a 5 shows on the red die?
25 81
1 36 9

10. A bag contains 4 red, 4 green, and 7 blue marbles
A bag contains 4 red, 4 green, and 7 blue marbles. Three are selected in sequence without replacement. What is the probability of selecting a red, a green, and a blue marble in that order?
8 195 10