diff --git a/.classpath b/.classpath
index 51a8bba..cf9c6b5 100644
--- a/.classpath
+++ b/.classpath
@@ -1,6 +1,6 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<classpath>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
-	<classpathentry kind="src" path="src"/>
-	<classpathentry kind="output" path="bin"/>
-</classpath>
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/jdk1.8.0_171"/>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>
diff --git a/src/practice01/Prob1.java b/src/practice01/Prob1.java
index c038781..adda9c9 100644
--- a/src/practice01/Prob1.java
+++ b/src/practice01/Prob1.java
@@ -4,9 +4,14 @@
 
 public class Prob1 {
 	public static void main(String[] args) {
-		Scanner scanner = new Scanner( System.in );
-		
-		
+		Scanner scanner = new Scanner(System.in);
+		System.out.print("수를 입력하세요 : ");
+		Scanner input_num = new Scanner(System.in);
+		int i = input_num.nextInt();
+		if (i % 3 == 0)
+			System.out.println("3의 배수입니다.");
+		else
+			System.out.println("3의 배수가 아닙니다.");
 		scanner.close();
 	}
 }
diff --git a/src/practice01/Prob2.java b/src/practice01/Prob2.java
index 32d40f0..821f97a 100644
--- a/src/practice01/Prob2.java
+++ b/src/practice01/Prob2.java
@@ -1,6 +1,27 @@
 package practice01;
 
+import java.util.Scanner;
+
 public class Prob2 {
 	public static void main(String[] args) {
+		System.out.print("숫자를 입력하시오 : ");
+		Scanner s = new Scanner(System.in);
+		int count = s.nextInt();
+		int min_num = 1;
+		int max_num = 11;
+		while (true) {
+			if (count > 0) {
+				for (int i = min_num; i < max_num; i++) {
+					System.out.print(i);
+				}
+			} else {
+				break;
+			}
+			count--;
+			min_num++;
+			max_num++;
+			System.out.println();
+		}
 	}
+
 }
diff --git a/src/practice01/Prob3.java b/src/practice01/Prob3.java
index 3b7ab3c..f9420b2 100644
--- a/src/practice01/Prob3.java
+++ b/src/practice01/Prob3.java
@@ -1,7 +1,32 @@
 package practice01;
 
+import java.util.Scanner;
+
 public class Prob3 {
-	
+
 	public static void main(String[] args) {
+
+		while (true) {
+			System.out.print("숫자를 입력하시오 : ");
+			Scanner s = new Scanner(System.in);
+			int input_num = s.nextInt();
+			int sum = 0;
+			if (input_num % 2 == 0) {
+				for (int i = 1; i <= input_num; i++) {
+					if (i % 2 == 0)
+						sum += i;
+
+				}
+				System.out.println(sum);
+
+			} else {
+				for (int i = 1; i <= input_num; i++) {
+					if (i % 2 != 0)
+						sum += i;
+				}
+				System.out.println(sum);
+			}
+			System.out.println();
+		}
 	}
 }
diff --git a/src/practice01/Prob4.java b/src/practice01/Prob4.java
index 7d38c33..febfe8e 100644
--- a/src/practice01/Prob4.java
+++ b/src/practice01/Prob4.java
@@ -1,9 +1,16 @@
 package practice01;
 
+import java.util.Scanner;
 
 public class Prob4 {
 
 	public static void main(String[] args) {
+		System.out.print("문자열을 입력하시오 : ");
+		Scanner s = new Scanner(System.in);
+		String input = s.nextLine();
+		for(int i = 0; i <input.length(); i ++) {
+			System.out.println(input.substring(0, i+1));
+		}
 	}
 
 }
diff --git a/src/practice01/Prob5.java b/src/practice01/Prob5.java
index d8d08ad..aa602d4 100644
--- a/src/practice01/Prob5.java
+++ b/src/practice01/Prob5.java
@@ -3,5 +3,28 @@
 public class Prob5 {
 
 	public static void main(String[] args) {
+		int start = 1;
+		String clap = "짝";
+		while (start < 1000) {
+			int count = 0;
+			String check = Integer.toString(start);
+			for (int i = 0; i < check.length(); i++) {
+
+				String check1 = check.substring(i, i + 1);
+				int check2 = Integer.parseInt(check1);
+				if (check2 % 3 == 0 && check2 != 0) {
+					count++;
+				}
+			}
+			if (count > 0) {
+				System.out.print(start + "  ");
+				for (int i = 0; i < count; i++) {
+					System.out.print(clap);
+				}
+				System.out.println();
+			}
+
+			start++;
+		}
 	}
 }