The Application of "Sets" of Discrete Mathematics everyday in life

Mathematics is related to something that can be calculated or something expressed in terms of quantity (number). There are so many economic variables (concepts) that are quantified, such as the price of goods, the amount of goods demanded and offered, the money supply, the level of profit sharing margin, national income, investment level, and so on. Mathematics does not only play a role in quantifying economic variables, but also explores the relationship between economic variables. The relationship of an economic variable with other economic variables is often expressed in the form of an economic model. Because economic variables can be quantified, these economic models can be expressed in the form of mathematical symbols / models.


Background
Mathematics is a lesson that has a lot of formulas and also people who learn it must memorize a lot. Memorizing is not enough, because we must try to apply it in everyday life. Mathematics is also a medium that is able to solve problems, from simple problems to even complex problems.
Often we ask ourselves, "what are the benefits of learning mathematics? Is mathematics used in everyday life? What are the benefits of the set? " Surely we often ask this question to ourselves, to our friends, or to our math teacher. This question occurs because we are already upset or give up to learn a lesson that they think is very boring and unnecessary.
"Set". Some people don't know what the meaning of the set is so that sometimes people misinterpret it. Actually the word set is related to grouping. There are some who have known the association of associations with groupings, finally they conclude themselves even though they have not been able to describe it clearly.
Set is commonly used in mathematics and daily life. In everyday life we find that understanding as in the Amikom Student Association, a collection of books, stamp collections, study groups, and others. The set and collection words are used in the same definition, even though both have the same meaning. Thus the word set and collection.
The benefit of the association is to help people who work to think rationally, critically, straightly, steadily, orderly, methodical and coherent, improve their ability to think abstractly, meticulously, and 154. CSRID Journal, Vol. 10 No. 3 Juni 2018, Hal. 153-161 ISSN: 2085-1367https://www.doi.org/10.22303/csrid.10.3.2018.153-161 eISSN :2460 objectively, improve intelligence and improve abilities sharply and independently, with and encourage people to think for themselves by using systematic principles, increasing love for truth and avoiding thinking errors, errors and errors, are able to analyze events.

A. Definition of Sets
The set was introduced by George Cantor (1845 -1918), a German mathematician. He is the Father theory of Sets, because he was the first to develop the branch of mathematics. He said that the sets is a collection of objects. These items can be abstract or concrete objects. Basically, objects in a set do not have to have the same character/character or set is a collection of clearly defined objects or objects.
Sets are The set is a collection of objects or objects or symbols that have a meaning that can be clearly defined which are members of the set and which are not members of the set. In our daily lives, we often talk about discrete objects, such as books, pencils, classes, computers, students, and so on. Or we can tell, The set is a collection of objects or symbol that have a meaning that can be clearly defined which are members of set and which are not the members of set.
Let's look at the objects around us, for example a group of students B, a group of students studying in class Y, etc. if we observe all the objects around us that are used as examples above can be clearly defined and which members can be distinguished and which are not. Objects contained in the set are called elements, members, and unsure.
Delicious food set, beautiful girl set and beautiful flower set are examples of sets that cannot be clearly defined. Why? Because of the delicious food, the beauty of the girl and the beauty of flowers for some people is very relative. The beauty of flowers for someone is not necessarily beautiful for others. So it's relative for everyone. Object or objects included in the set are called members or elements of the set. Generally the writing of sets uses capital letters A, B, C and so on, and the set members are written in lowercase letters.
Intuitively the set is a collection of objects that have certain properties. The objects in the set are called members (elements) of the set. The particular nature of the members of the set is called the nature of the set. The nature of the set is clearly defined.

B. Type of Sets
There are a lot of type of Sets : 1. Subset Set A is said to be a Subset of Set B written A ⊂ B , if each member A is member of B. they have some Requirements : If A ={1,2,3,4,5} and B={2,4} , then B ⊂ A Because every elements of B is set member of A. Explanation : From the definition above, the set of parts must have an element of set A also an element of set B. The meaning of the two sets must be interrelated.

Nullset
Nullset is a set that does not have the same member element at all. Nullset have some Requirements : Blank set = A or {} Blank set is single. An empty set is a subset of each set. NOTE : an empty set cannot be declared {0} because {0} ≠ {} Explanation : from the definition above the blank set is a set that does not have a single member and usually an empty set is denoted by the Greek Letter ø (phi).

Universes set
The set of universes is usually denoted by "U" or "S" (Universum) which means a set that contains all the members discussed or in the other words the set of obejcts being discussed.

Equal set
If each member of set A is also a member of set B, and vice versa. Denote by A= B Requirements : two sets of members must be the same. Example : A = {q,w,e} B = {q,w,e} then A = B Equal set or set is the same, has two sets whose members are the same member of set A {q,w,e} then set B will also have members namely {q,w,e}.  CSRID Journal, Vol. 10 No. 3 Juni 2018, Hal. 153-161 ISSN: 2085-1367https://www.doi.org/10.22303/csrid.10.3.2018.153-161 eISSN :2460 7. Equivalent set The equivalent set is a set whose members are as many as other sets. They have some requirements : Cardinal numbers are expressed by notation n(A) A≈B, said to be aquivalent to set B, Example : 2. State the set by mentioning or registering its members, this method is also called Description. Namely by the way the members of the set are written in curly brackets and between members with one another are separated by commas.

Disjoint set
Example : A = {apple, watermelon, guava, orange, mango} This is for groups with few or limited members B = {Jogjakarta, Semarang, Palembang, Padang, … , Aceh} This is for groups with many but limited members C = {2,3,4,5,6,10,11,…} This is for groups with a large number of members 3. State the set with the set-up notation, by writing down general characteristics or general characteristics (roles) of its members. The way to declare a set with a set-up notation is to follow the following rules : a. The object or object is represented by a variable (a,b,c,…,z) b. Writhe down the terms of membership behind the sign '|' Example : Read : the set of each x such that x is less than 7 and x is the real number B = {(x,y) | y + x = 7, x and y is real number} Read : a pairs set of x and y such that y + x is equal to 7 for x and y is the real number.
4. The set can also be presented graphically (Venn Diagram) Presentation of setd with Venn Diagrams was discovered by a British Mathematician named John Venn in 1881. The set of universes by rectangles and other sets with circles in the quadrilateral.

E. The Law of Algebra in the Sets
The laws of the set are called set algebra laws. There are many laws are contained in the set algebra, but here only spelled put 1-1. Some of these laws are similar to algebraic laws on real number systems such as a ( b + c ) = ab + ac ,namely distributive law.

F. The benefits of Sets
By studying the Sets, it is expected that the logical ability will be increasingly honed and will spur us so that we are able to think logically, because in life logic has an important role because logic is related to reason. There are many logical uses include : 1. It can be helping everyone who learns logic to think rationally, critically, straightly, permanently, orderly, methodically, and coherently. 2. It can be improve the ability to think abstractly, carefully, and objectively. 3. It can be increase intelligence and improve the ability to think sharply and independently. 4. It can be forching and encouraging people to think for themselves by using systematic principels. 5. It can be increase love of truth and avoid mistakes in thingking, errors and error 6. It can be able to analyze an event There are some example of sets :

G. The practice a Sets in daily Life
A sets is some collection that is considered as a unit that is combined in a circle. There are so many implementations that we can see in everyday life. Some examples that are often used by teachers and lecturers are examples of hobbies, because many hobbies in life are the same. For example, there are hobbies who play soccer, while those who like playing basketball. But as for those who like both. In this case we can use the set to know it. Example questions There are 20 children in the class and 5 people who like soccer, 5 people like basketball, 10 people like both. And the results will be like this. There are many things that we can see in everyday life about the set. Where we are grouped every time in making a big project. For sure, every project like that needs grouping. There was a team that made about this and the tone of the team that made it. Some people help both because of experts in both. Like a set curve in a work environment.

RESEARCH METHODS
Member of research, the name of sets mostly using capital letters like A,B,C, and X. while members of sets are usually denoted by lowercase letters such as a,b,c,x,and y. for example H is the sets of all vowels in the latin alphabet so the objects included in the set H are a,i,u,e, and o. the objects that enter in a set are referred to as members of the set. The notation for declaring members of a set is "" while the notation for non-members is "". Therefore a H, iH, u  H, e  H, and o  H while b  H, c  H and d  H. the term member used above can be replaced with the term elements or element. The special symbols used in set teory are :