INTRODUCTION TO PROBABILITY

1. By: CHRISTINE P. YNOT
LNHS teacher

2. This lesson will help you:
• Analyze games and other practical probabilistic events through a
detailed and cooperative problem – solving
• Classify events as mutually exclusive or independent
• Describe probability according to its classification and event
relationships

3. RECALL
Drill
1. It is a possible result of an experiment.
2. It is a collection of outcomes or the
desired outcome of the experiment.
3. A process that produces an outcome
which can be random or not
A. Experiment
B. Event
C. Outcome
D. Sample Space

4. Form 5 groups with 4 members. Two members of the
will roll two dice twenty times and record your observation
from the table provided for you. After this, do the
computations and answer the corresponding questions, as
group. Report your group observation in a class.
GROUP ACTIVITY

5. TITLE:
Member Frequency of
both dice
showing odd
numbers
Number of trials
____________________
_______________
Total: Total:
Total freq. of both
dice having odd
numbers . = ______
Total number of trials
How many different outcomes are there
for two dice showing both odd numbers?
Die – a small cube marked on each
face with from one to six dots, usually
in pairs
Plural: dice

6. How many different outcomes are there
for two dice rolled?
What is the quotient between these two
values?

7. Are these two quotient values nearly the
same? How can you relate these two
quotients?

8. REALIZATIONS…
1. There are uncertain situations and conditions in
life.
2. Situations can only be assumed and predicted
but CANNOT BE ASSURED.

9. WHAT IS PROBABILITY?

10. DICE ACTIVITY
Roll two dice and have both odd numbers turn up
EXPERIMENT EVENT

11. What activities in school or at home
involve uncertainty and randomness

12. What activities in
school or at home
involve uncertainty
and randomness?

13. Numerically, probability is the quotient between
the number of _____________________
in the desired ____________and the entire
_______________________of the
_____________________.
outcomes experiment
outcomesevent
Sample space experiment
outcomes
event
experiment
Sample space

14. Numerically,
Pr(both odd numbers)=
𝑛(𝑏𝑜𝑡ℎ 𝑜𝑑𝑑 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 𝑓𝑜𝑟 𝑡𝑤𝑜 𝑑𝑖𝑐𝑒)
𝑛(𝑟𝑜𝑙𝑙 𝑡𝑤𝑜 𝑑𝑖𝑐𝑒)
 Pr(both odd numbers) is the probability of an event.
 n(roll two dice) is the number of outcomes of the
experiment.
 n(both odd numbers for two dice) is the number of
outcomes of a desired event.

15. PROBABILITY SCALE
Pr(A) = 0
This means that there
is no chance that
Event A will occur
Pr(A) = 0.5
This means that there is
1chance out of 2 that
Event A will occur. This
chance of success is half.
Pr(A) =1
This means that Event A
will occur each time the
experiment is done.

16. This probability scale tells us that the
chance of occurrence of any Event A is
only between zero to one.
What does it imply if ever Pr(A)<0?
What does it imply if ever Pr(A)>1?

17. PROBLEM SOLVING

18. PROBLEM SOLVING
Example 1:
TOSSING A COIN ROLLING TWO DICE
CHOOSING LOTTO
BALLS
EXPERIMENTS

19. PROBLEM SOLVING
Example 2:
Which of the following is an event or outcome?
Pick a card from a
poker deck
Landing on red in a
roulette
Select a bingo ball

20. Example #3:
Your class is planning to have Kris Kringle on your
upcoming Christmas party with a theme of
something bright and happy.


21. Tihik
Kidlat
Dugdog
Ngitngit
Himsug
Liwanag
Datuh
Sah
Gugma
Friends
Ngutngut
Kau

22. 4. What is the probability that your monito or Monita is both
in your study group and also your friend?
5. What is the probability that your monito or monita is neither
in your study group nor your friend?
Boardwork #2

23. • 1. How can you differentiate intersection from union, in
terms of events?
• 2. How can you describe the illustration of mutually
exclusive events?

24. A. Manufactuing
B. MANAGEMENT
C. INSURANCE
Choose from this 3 situations wherein
determining the probability of an event is
important.

25. EXERCISES
DEPENDENT ASSESSEMENT:
10 – item SEATWORK
INDEPENDENT:
11 – item test

26. 1. Probability of getting yellow.
2. Probability of getting 9.
3. Probability of getting even numbers.
4. Probability of getting odd numbers.
5. Probability of getting purple.
6. Probability of getting a no. less than 9 but greater than 7.
7. Probability of getting a negative number.
8. Probability of getting numbers greater than 0 but less than 9.
9. Probability of getting light blue.
10.Probability of getting primary colors.
SEATWORK
(10 MINUTES)

27. Checking…

28. 15 – MINUTE TEST
11 – ITEM TEST
Refer to the hand – outs)

29. ASSIGNMENT
•Pierre de Fermat is one of the Pioneers in the
study of modern probability theory. Even if he was
a lawyer by profession, he had enormous
contribution in the field of the probability. Write a
biographical journal about him and focus on his
attitudes that will help you to be a better student.

30. By: CHRISTINE P. YNOT

33. What is the probability that you monito or Monita is your friend?