1. Probability (Unit 5) Is the likelihood or chance of an even occurring.
Favourable Outcomes
Total Possible Outcomes
What is the probability of rolling the number 2 on a dice?
How many favourable outcomes?
How many possible outcomes?
Place these numbers into the fraction
above…

2. How to express probability
Probability can be written in 3 ways...
As a fraction = 1/6
As a decimal = 0.16
As a percent
0.16 x 100% = 16%
How often will the
number 2 show up
when rolled?

3. Determine the probability
First you must find the possible outcomes (total) and then
the favourable outcomes (what you’re looking for). Then
place them into the probability equation.
Rolling an even number on a dice?
Pulling a red card out from a deck of cards?
Using a four colored spinner to find green?
Selecting a girl from your class?
Favourable Outcomes
Total Possible Outcomes

4. Determine the probability
A cookie jar contains 3 chocolate chip, 5 raisin, 11 Oreos,
and 6 almond cookies. Find the probability if you were to
reach inside the cookie jar for each of the cookies above.
Type of Cookie
Chocolate Chip
Raisin
Oreo
Almond
Fraction
Decimal
Percent
Ratio

5. Determine the probability
Page 163: # 3ab, 5, 7
Page 164: # 9

6. Organized Outcomes Independent Events:
The outcome of one event has not effect on the outcome of another event
Example:
ROCK
PAPER
SCISSOR
Tails Head

7. Organized Outcomes Sample Space:
All possible outcomes of an experiment
What is the probability of Paper/Head?
What is the probability of tails showing up?
Sample Space
Head
Tail
Rock
Paper
Scissor

8. “Tree Diagram” to represent Outcomes
H T
Coin Flip
R P S R P S
Rock, Paper, Scissor
H, Rock T, Rock
H, Paper T, Paper
H, Scissor T, Scissor
Outcome

9. “Spider Diagram” to represent Outcomes
Rock
Rock
Paper
Paper
Scissor
Scissor

10. Organized Outcomes You can find the sample space of two independent
events in many ways.
Chart
Tree Diagram
Spider Diagram
Your choice, but showing one of the above
illustrates that you can find the favourable and
possible outcomes for probability.

11. Organized Outcomes
Page 169: # 5, 8
Page 170: # 9, 10

12. Probabilities of Simple Independent Events
Random:
an event in which every outcome has an equal chance of
occurring.
A school gym has three doors on the stage and two back
doors. During a school play, each character enters through
one of the five doors. The next character to enter can be
either a boy or a girl. Use a “Tree Diagram” to determine
to show the sample space. Then answer the questions on
the next slide!

13. Probabilities of Simple Independent Events
Random:
an event in which every outcome has an equal chance of
occurring.
See Page 172 for your “Tree Diagram” of the school gym
doors!

14. Using a Table to DETERMINE Probabilities
How to determine probabilities:
Use “p” (or any other letter as the variable to represent
what you’re looking for) and divide it by “t” the total
outcomes. Then multiply your answer by 100%.
Equation stays the same: p/t x 100%
Use your results from the “tree diagram” of the gym doors
and place them into a table. Then determine the
probabilities for the scenarios on the next slide!

15. Using a Table to DETERMINE Probabilities
How to determine probabilities: p/t x 100%
Back Left (BL)
Back Right
(BR)
Left Stage
(LS)
Centre Stage (CS)
Right Stage
(RS)
Boy
BBL
BBR
BLS
BCS
BRS
Girl
GBL
GBR
GLS
GCS
GRS
Determine the probability for the scenarios below...
1. Of a boy using any right door?
2. Of anyone (boy or girl) using a stage door?
3. Of a girls using any of the doors?

16. Determine Probabilities
Page 175: # 6, 8
Page 176: # 13

17. Applications of Independent Events
Use Tree Diagrams, Charts or other graphic organizers to
solve probability problems.
How can you win at the game of “Sit & Save?”
RULES:
Stand up at the beginning of the round.
Two dice are rolled each round. You may collect the sum of your dice as long as a “6” does NOT appear. A “6” means all numbers before are cancelled and you get zero for that round.
After each roll you have two choices
Continue standing and roll again…hoping for no “6”
Sit and collect your total points!

18. Applications of Independent Events
How can you win at the game of “Sit & Save?”
Who had the highest score?
What is the possibility of a 6 appearing with 2 dice? (sample data)
Use the numbers above for each player to find who had the best probability (percent) of not rolling a 6.
Student Names
Round 1
Round 2
Round 3
Round 4
TOTAL

19. Interpret Outcomes
Use Tree Diagrams, Charts or other graphic organizers to solve
probability problems.
What are the 2 independent events?
What is the probability of the sum of these 2 events ending up to total “4”…
What is the probability of outcome having one 3 appear?

20. Interpret Outcomes What is the probability of red appearing?
What is the possibility of a black and green appearing?
What is the possibility of both events being two syllable words appearing?

21. Interpret Independent Outcomes
Page 181: # 6, 7
Page 182: # 9

22. Theoretical vs. Practical Probabilities
What are the chances of a boy and girl picking the same number
from Try this 10 times and tally your results (Practical) . Then
compare to your “theoretical answer.”
Practical
Boy
Girl
Theoretical 1 2 3 4 5
Boy B1 B2 B3 B4 B5
Girl G1 G2 G3 G4 G5

23. The expected probability of an event occurring.
Theoretical vs. Practical Probabilities
What are the chances of a boy and girl picking the same number
from Try this 10 times and tally your results (practical) . Then
compare to your “theoretical” answer.
Practical
The probability of an event occurring based on experimental results.
Boy
Girl
The expected probability of an event occurring.
Theoretical 1 2 3 4 5
Boy B1 B2 B3 B4 B5
Girl G1 G2 G3 G4 G5

24. Are your ready to be TESTED on “Probability?”
We have covered a lot of material in this unit. Do you have any
concerns or questions about any of the topics below?
Representing probability in different ways… (Pg. 158)
Types of sample spaces to find the probability (Pg )
Explain how to identify an independent event.
Determine the outcomes of two independent events. (Pg. 172)
Find the sum of different events…which sample space would be best to use?
Solve multiple probabilities… P(1,B) or P(Girls, Boys, 6)
Use diagrams to interpret data and probabilities. (Pg )
Compare experimental to theoretical probabilities. (Pg. 184)
If so, then you are ready for the test. For more practice and review of the test please
complete questions on page (5, 8, 9, 12, and 13). Make sure to check your
answers to the back of the book so you are prepared for the exam. As well, if you have
any questions please see me in the morning or at lunch before the exam! For extra
practice complete the “Practice Test” on pages Best of luck!