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.