⋅ P(A or B): probability of event A occurring or event B occurring during a single trial.
⋅ If events A, B are mutually exclusive:
- events A, B have no common outcomes.
- in the Venn Diagram, the circle for A and the circle for B have no area of overlap.
- P(A or B) = P(A) + P(B)
⋅ If events A, B are not mutually exclusive:
- events A, B have common outcomes.
- in the Venn Diagram, the circle for A and the circle for B have an area of overlap representing the event “A and B”.
- P(A or B) = P(A) + P(B) – P(A and B)
Mutually Exclusive VS. Not Mutually Exclusive
Consider the experiment of rolling a die.
There are 20 students in a class. 9 students like pizza and 7 students like pasta. Of these students, 3 students like both. Determine the probability that a randomly selected student in the class like pizza or pasta
A card is drawn from a standard deck of 52 cards. Determine the probability that:
Use the following information to determine whether the events A, B are mutually exclusive.
Addition rule for “OR”
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