# Not Mutually Exclusive Events

Two events are called not mutually exclusive if they have at least one outcome in common. If the two events and are not mutually exclusive events, then . Similarly, and are not mutually exclusive events if . Thus they must have at least one common point between them.

Consider a sample space:

Let and

Here

Thus, i.e. exist. Here and are not mutually exclusive events. consists of outcomes which are common to both and . The figure below shows a Venn diagram in which and are not mutually exclusive events. An area under is common with . If the event is a part of event , then . This is shown in the figure: