1. A well define collection of objects that shares a common characteristics
2. An object inside a given set.
3. A set that has an infinite number of elements.
4. A set that has an empty element.
5. A set that has a finite number of elements.
6. The total number of element in a given set.
7.U = {x/x is a vowel letter in English alphabet. _
8. The cardinality of set A.
9. a is an element of B.
10. The union of set A and B.
11. The intersection of A and B.
12. Set D is an empty set _
13. The cardinality of the union of A and B
14. The complement of set A.
15. The union of set A and B intersection C. ​