concepts of probability

1. PROBABILITY
THEORETICAL PROBABILITY

2. Lesson objectives:
 Define the important concepts in probability
 Work out the probability of certain events using
the formula for probability
 Apply the probability formula
 Represent probability using Venn diagrams
 Conditions for mutually exclusive

3. Revision
 Probability is the study of HOW likely it is that an event will happen.
The following are typical probability questions
 What is the chance of getting a head when flipping a coin
 What is the chance of getting a 2 when rolling dice NB:ONE DIE
TWO DICE

4. Important concepts in probability
 An Event is a happening or an activity that has outcomes or results
example: Rolling an even number is an event with certain
outcomes
 An outcome is the possible results of an event
example: possible outcomes of rolling a die are: 1;2;3;4;5;6
 Sample space is the set of all possible outcomes.

5. probability representation
 Probability formula
Probability=
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑓𝑎𝑣𝑜𝑢𝑟𝑖𝑏𝑙𝑒 𝑜𝑢𝑡𝑐𝑜𝑚𝑒𝑠
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑜𝑠𝑠𝑖𝑏𝑙𝑒 𝑜𝑢𝑡𝑐𝑜𝑚𝑒𝑠
 Probability always lie between 0 and 1, measured as fraction or as decimal
example: The probability of getting a head when flipping a coin is
1
2
/0.5
 If probability is shown as a percentage, then it lies between 0% and 100%

6. Venn diagrams
 We use Venn diagrams to help us rep[resent different events.(Venn diagrams
consist of circles and a rectangle)
 The rectangle (S) represents the sample space(all the possible outcomes)
 Each circle inside the rectangle represent different events
 If the circle intersects, the intersection shows which outcomes belong to both
events
(S)

7. Mutually exclusive events
 Mutual: applies to two or more people or events
 Exclude: To keep out, not allow in
 Mutually exclusive: Both events keep the other out, so there is no outcome
that can in both events at the same time
YOU CANNOT BE MALE AND FEMALE AT THE SAME TIME

8. CONDITIONS FOR MUTUALLY EXCLUSIVE
EVENTS
 P(A and B)= 0

9. THANK YOU

10. References
 https://www.slideshare.net/Qwizdom/qwizdom-maths-
probability?qid=6a6158b2-be7f-4ca1-80be-
3019a51f4a10&v=&b=&from_search=2
 https://www.slideshare.net/charliechen9883/maths-presentation-on-
probability-distribution?qid=6a6158b2-be7f-4ca1-80be-
3019a51f4a10&v=&b=&from_search=5
 https://www.slideshare.net/svsonwalkar/maths-probability?qid=64fcc2f1-
70f3-4eae-a0fa-613ee3b926d4&v=&b=&from_search=8