This document discusses probability and how it is measured on a scale from 0 to 1. It provides examples of calculating the probability of rolling a 4 on a dice and drawing a blue marble from a bag containing marbles of different colors. It also defines mutually exclusive probability as the probability of events that cannot occur simultaneously, such as drawing a king and an ace card, which is calculated by adding the individual probabilities. An example problem is given to calculate the probability that a student chosen at random from a French club is a junior or senior.

1. PROBABILITY
THE LIKELIHOOD OF AN EVENT HAPPENING

2. HOW DO WE FIND PROBABILITY…
• In general,
• Probability is between 0 and 1. A probability of 0 means it will
never happen, and a probability of 1 means it will most certainly
happen.

3. PROBABILITY EXAMPLE:
• What is the probability of rolling a 4 on a dice?
1
6
• In a bag that contains 6 red marbles, 3 blue marbles and 9 white marbles, what is the probability of
choosing a blue marble?
3
18

4. MUTUALLY
EXCLUSIVE
PROBABILITY
(OR PROBABILITY)
• Two events that can not
happen at the same time…a
card being a king and an ace.
• P(A or B) = P(A) + P(B)

5. MUTUALLY EXCLUSIVE EXAMPLE

6. YOU TRY: The French Club has 16 seniors, 12
juniors, 15 sophomores, and 21 freshmen
as members. What is the probability that a
student chosen at random is a junior or a
senior?

7. YOU TRY: The French Club has 16 seniors, 12
juniors, 15 sophomores, and 21 freshmen
as members. What is the probability that a
student chosen at random is a junior or a
senior?