When two events are mutually exclusive they cannot happen at the same time. Let's consider an example of rolling a die.
Here, rolling 1 and rolling 6 are mutually exclusive events because we cannot roll 1 and 6 at the same time using one die. However, since the probability of rolling each number is 16, the sum of the probabilities of these two events is not equal to 1.
1/6+ 1/6≠ 1
This is because we have other possible outcomes in the sample space. If we would add the probabilities of all 6 possible outcomes, then it would give us 1.
