A good name for the set {a, b, c, ..., x, y, z} is EnglishAlphabet. Determine the set EnglishAlphabet - {a, e, i, o, u}? What is a good name for the set we have removed? For the resulting set that is left?
For finite sets, the cardinality of the set is the number of elements in the set. For example, the cardinality of the set EnglishAlphabet is 26.