diff --git a/src/src/minju/Car.java b/src/src/minju/Car.java
new file mode 100644
index 0000000..27d6c8a
--- /dev/null
+++ b/src/src/minju/Car.java
@@ -0,0 +1,48 @@
+package minju;
+
+public class Car {
+    static Integer WHEEL_COUNT = 4;
+    private String color;
+    private String brand;
+    private Integer maxSpeed;
+    private Integer currentSpeed;
+    private String fuel;
+
+    public Car(String inputcolor) {
+        this.color = inputcolor;
+        this.brand = "테슬라";
+        this.maxSpeed = 250;
+        this.fuel = "전기";
+        this.currentSpeed = 0;
+    }
+
+    public Car(String inputColor, String inputBrand, int maxSpeed, String fuel) {
+        this.color = inputColor;
+        this.brand = inputBrand;
+        this.maxSpeed = maxSpeed;
+        this.fuel = fuel;
+        this.currentSpeed = 0;
+    }
+
+    public String 무슨색차니() {
+        return this.color;
+    }
+
+    public String 무슨브랜드와무슨색을가지고있니() {
+        return "브랜드는 " + this.brand + " 색은 " + this.color;
+    }
+
+    public void 가속하기() {
+        this.currentSpeed += 1;
+    }
+
+    public void 감속하기() {
+        this.currentSpeed -= 1;
+    }
+
+    public Integer 현재속력은() {
+        return this.currentSpeed;
+    }
+
+
+}
diff --git a/src/src/minju/Case1.java b/src/src/minju/Case1.java
new file mode 100644
index 0000000..a65551c
--- /dev/null
+++ b/src/src/minju/Case1.java
@@ -0,0 +1,31 @@
+package minju;
+
+import java.util.Scanner;
+
+public class Case1 {
+    public void gameStart(int randomNum) {
+        //int : 타입
+
+        Scanner sc = new Scanner(System.in);
+        //Wrpper 클래스: 코드가 작성되있음(1897줄) -> 객체 지향(외부에서 내부 구현 몰라도 된다!)
+
+        //그냥 형변환하는 것 구현 하기 힘들기 때문에!
+        //  user_input.floatValue();
+        //  user_input.toString();
+        String string = "아직 못맞춤";
+
+        //string =="아직 못맞춤"   원래는 equals 사용해야하는데  == 도 가능하다!
+
+        while (true) {
+            Integer user_input = Integer.parseInt(sc.nextLine());
+            if (randomNum < user_input) {
+                System.out.println("DOWN");
+            } else if (randomNum > user_input) {
+                System.out.println("UP");
+            } else {
+                System.out.println("GOOD");
+                break;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/src/minju/Student.java b/src/src/minju/Student.java
new file mode 100644
index 0000000..510fd87
--- /dev/null
+++ b/src/src/minju/Student.java
@@ -0,0 +1,40 @@
+package minju;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Student {
+    private String name;//이름
+    private String hobby;//취미
+    private Integer number;//학번
+    private Integer grade;//학년
+    private String school_name;//학교 이름
+    private String major;//전공
+    private List<String> subjectList;
+
+    private Integer credit;
+
+    public Student(String name, String school_name, Integer grade, Integer number, String major, String hobby) {
+        this.name = name;
+        this.school_name = school_name;
+        this.grade = grade;
+        this.number = number;
+        this.major = major;
+        this.hobby = hobby;
+        this.subjectList = new ArrayList<>();
+    }
+
+
+    public String 전공이무엇이니() {
+        return major;
+    }
+
+    public void 과목추가(String subject) {
+        subjectList.add(subject);
+    }
+
+    public void 학점추가(Integer num) {
+        this.credit += num;
+    }
+
+}