Mutually exclusive

If two events can’t happen at the same time then they are said to be mutually exclusive.

Exclusive means excluding, meaning shutting out. If someone is excluded then they can’t take part. For example, if a student repeatedly behaves badly at school then they could be excluded.

Mutually means doing to each other. If two people have mutual respect for each other then they both respect the other.

So, mutually exclusive means both shutting the other out.

So, if two events can’t happen at the same time then they both exclude the other and are said to be mutually exclusive.

In our example of picking a card from a pack of cards, picking a 7 excludes picking a queen and picking a queen excludes picking a 7. These events are mutually exclusive.

Picking a 7 doesn’t exclude picking a club though because it is possible to pick the 7 of clubs. These events are not mutually exclusive.