ObjectiveSWBAT find the probability of simple events

What is probability?

- used to measure the chance of an event happening

- ratio that compares the number of favorable outcomes to the number of possible outcomes.

What two numbers is the probability of any event between?

P(event) =# of favorable outcomes# of possible outcomes

1. Suppose a number cube is rolled. What is the probability of rolling a 4 or a 5?

There are 2 numbers on the number cube that are a 4 or a 5: 4 and 5.There are 6 possible outcomes: 1, 2, 3, 4, 5, and 6.

Answer:

A. AB. BC. CD. D

Example 1 CYP

A B C D

0% 0%0%0%

Suppose a number cube is rolled. What is the probability of rolling a number that is divisible by 3?

A. AnsA

B. AnsB

C. AnsC

D. AnsD

1. Dionne drew a marble at random from a bag of marbles that contained 5 red marbles, 4 yellow marbles, 2 green marbles, and 1 pink marble. What is the probability of Dionne drawing a yellow marble?

2. What is the probability of drawing a pink or red marble?

P(event) =# of favorable outcomes# of possible outcomes

What is the probability of tossing heads?

Theoretical Probability : what should occur in an experiment

What is the probability of tossing heads?

Experimental Probability – What actually occurs when repeating a probability experiment many times.

Toss Outcome

12345678910

Example 1Use a Tree Diagram to Count Outcomes

GREETING CARDS A greeting card maker offers three birthday greetings in four possible colors, as shown below. Draw a tree diagram to find the number of cards that can be made from three greeting choices and four color choices.

Example 1Use a Tree Diagram to Count Outcomes

You can draw a diagram to find the number of possible cards.

Answer: There are 12 possible cards.

A. AB. BC. CD. D

Example 1 CYP

A B C D

0% 0%0%0%

A. 3B. 5C. 8D. 15

ICE CREAM An ice cream parlor offers a special on one-scoop sundaes with one topping. The ice cream parlor has 5 different flavors of ice cream and three different choices for toppings. How many different sundaes can be made?