The document provides an introduction to basic probability concepts including: - Sample space is the set of all possible outcomes of an experiment. - An event is a subset of outcomes within the sample space. - Probability is expressed as a ratio of favorable outcomes to total outcomes. - Probability ranges from 0 to 1, with 0 being impossible and 1 being certain. - Complementary events have probabilities that sum to 1.

1. What is the probability that the sky will fall?
Write your answer as a fraction.
Do not discuss with a neighbour.
An Introduction to Probability
http://mathforum.org/dr.math/faq/faq.prob.intro.html
Chicken Little by flickr user damonj74

2. Some vocabulary ...
Probability: the branch of mathematics that deals with chance.
Sample Space (Ω): the set of all possible outcomes for a given
quot;Experimentquot; represented by capital omega Ω.
Event (E): A subset of the sample space. A particular occurance
in a given experiment.
Simple Event: The result of an experiment that is carried out in
a single step.
Example: Flip a coin. The result is heads
(a simple event)
Compound Event: The result of an experiment carried out in two
(or more) steps.
Example 1: Flip a coin and roll a die - 6 .The result is {H,6}
Example 2: Flip a coin twice. The result is {H,T}

3. Calculating the Probability of Event A
number of favourable
outcomes
sample space
Probability can be expressed as:
- a Ratio
- a Fraction IMPORTANT: Probability of any event
- a Decimal is always a number between 0 and 1.
- a Percent

4. Certain Event: an event whose probability is 1
Example: roll a die - 6 and get a result less than 10
Impossible Event: an event whose probability is 0.
Example: roll a die - 6 and get a 7
Complimentary Event: the compliment of E is E':
If P(E) = a then P(E') = 1-a
Example: Given a standard deck of cards, a card is drawn at
random.
P(spade) = (13/52) = (1/4)
P (not a spade) = 1 - (1/4) = (3/4)

5. Determine the sample space when a fair die is rolled once.
Solution: It is possible to roll a 1, 2, 3, 4, 5 or 6.
This is the sample space. {1, 2, 3, 4, 5, 6}
Determine the sample space for rolling a six sided die and flipping
a coin.

6. Determine the probability of rolling a 2 when rolling a fair die.
Determine the probability of getting a head and an odd number
when rolling a die and flipping a coin.