To find the probability of mutually exclusive events, you can use a simple method called the addition rule. Here’s how it works:

1. What are Mutually Exclusive Events?
   Two events are called mutually exclusive if they cannot happen at the same time.
   For example, when you roll a die, you can get either a 2 or a 5, but you can’t roll both numbers at once.

2. The Addition Rule:
   You can find the chance of one or the other event happening using this formula:
   Probability of A or B = Probability of A + Probability of B
   This is written as:
   $P(A \cup B) = P(A) + P(B)$

3. A Simple Example:
   Let’s say the chance of rolling a 2 (event A) is:
   $P(A) = \frac{1}{6}$
   And the chance of rolling a 5 (event B) is:
   $P(B) = \frac{1}{6}$

Now, if you want to know the chance of rolling either a 2 or a 5, you add these two probabilities together:
$P(A \cup B) = P(A) + P(B) = \frac{1}{6} + \frac{1}{6} = \frac{2}{6} = \frac{1}{3}$

So, the chance of rolling a 2 or a 5 is 1 out of 3.

Using the addition rule is an easy way to find the probability of mutually exclusive events!