Pinellas County is a county located in the state of Florida. As of the 2010 census, the population was 916,542. Its county seat is Clearwater, and its largest city is St. Petersburg. Pinellas County is included in the TampaâSt. PetersburgâClearwater, Florida Metropolitan Statistical Area.
Nowadays, we can say in plain English: A set is a well defined collection of objects. The elements or members of a set can be anything: numbers, characters, words, names, letters of the alphabet, even other sets, and so on.
When we define a set, if we take pieces of that set, we can form what is called a subset. So for example, we have the set {1, 2, 3, 4, 5}. A subset of this is {1, 2, 3}. Another subset is {3, 4} or even another, {1}. However, {1, 6} is not a subset, since it contains an element (6) which is not in the parent set.hen our sets included integers. The universal set for that would be all the integers. In fact, when doing Number Theory, this is almost always what the universal set is, as Number Theory is simply the study of integers.