The union of two sets is a new set that contains all of the element that are in at least one of the two sets. The union is represented by a ∪ in the between the sets. An example of this is A, being a set of even numbers between 16 and 24 and B, a set of numbers less than 32. The union of A and B is set B. This should be written as A ∪ B{ 1, 2, 3, ..., 31} Set A is a subset of set B, all the elements in set A is in set B. The numbers should not be repeated. If a null set or an empty set is formed with set B the union would be all the element in set B.
On another hand, the intersection of two sets is a new set that contains all the element that are in both sets. The intersection is represented with a ∩ in between the sets similar to union. Lets take the same sets written above and intersect it with each other. The intersection of set A and B is set A. This will be written as A ∩ B { 18, 20, 22} Set a A is a subset of set B but instead of finding the union of these two sets we are finding the intersection. All the numbers in set A is in set B so the intersection of the two sets is set A. If a null set or an empty set is formed with set B the intersection would be an empty set because there aren't any common elements as the null set is empty.