Is the following set null or not? The set of students in your class who have been to the moon.
The question asks us whether a certain set is null or not. A null set is a set with nothing in it. It’s an empty set. And the notation for this is the two braces that we normally draw for sets but with nothing in between. So let’s think about the set that’s mentioned in the question.
We could draw a circle. And in it, we could ask every student in your class has been to the moon to write their name. How many names would there be? Obviously, there wouldn’t be any. None of the students in your class have been to the moon. And so, if we wrote this set using braces, we would have to draw the braces with nothing in between. There are no names we could write. This is a null set.
There are no students in your class that have been to the moon. So the set containing these students is going to be empty. It’s a null set.