# Probability: Mutually Exclusive Events

How to find the probability of independent events: formula, 1 example, and its solution.

## Formula

Mutually exclusive events are the events

that cannot happen together.

So, if A and B are mutually exclusive events,

then P(A and B) = 0.

Recall that

P(A or B) = P(A) + P(B) - P(A and B).

Probability: A or B

P(A and B) = 0

So P(A or B) = P(A) + P(B).

## Example

Solution

Solution (Detail)

Picking a blue marble (A)

and

picking a green marble (B)

cannot happen together.

(You can pick only one marble.)

Then these two events are

mutually exclusive events.

P(A) = 0.3

P(B) = 0.4

Then

P(A or B) = 0.3 + 0.4.

0.3 + 0.4 = 0.7

So 0.7 is the answer.