diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..9c3fff9
Binary files /dev/null and b/.DS_Store differ
diff --git a/Challenge/Hongryeol/1.arry/solve.js b/Challenge/Hongryeol/1.arry/solve.js
index 7ffd8bd..93de6ad 100644
--- a/Challenge/Hongryeol/1.arry/solve.js
+++ b/Challenge/Hongryeol/1.arry/solve.js
@@ -1,4 +1,7 @@
 // # 문제1 : 배열의 삭제
 // 다음 배열에서 400, 500를 삭제하는 code를 입력하세요.
 
-var nums = [100, 200, 300, 400, 500];
\ No newline at end of file
+var nums = [100, 200, 300, 400, 500];
+
+// 정답 
+// nums.splice(3,2);
\ No newline at end of file
diff --git a/Problems/2.arryMethd/README.md b/Challenge/Hongryeol/2.arryMethd/README.md
similarity index 100%
rename from Problems/2.arryMethd/README.md
rename to Challenge/Hongryeol/2.arryMethd/README.md
diff --git a/Problems/2.arryMethd/solve.js b/Challenge/Hongryeol/2.arryMethd/solve.js
similarity index 82%
rename from Problems/2.arryMethd/solve.js
rename to Challenge/Hongryeol/2.arryMethd/solve.js
index 4095544..8533fc5 100644
--- a/Problems/2.arryMethd/solve.js
+++ b/Challenge/Hongryeol/2.arryMethd/solve.js
@@ -8,4 +8,6 @@ var arr = [200, 100, 300];
 console.log(arr);
 
 출력
-[200, 100, 10000, 300]
\ No newline at end of file
+[200, 100, 10000, 300]
+
+// arr.splice(2, '1000');
\ No newline at end of file
diff --git a/Problems/3.type/README.md b/Challenge/Hongryeol/3.type/README.md
similarity index 100%
rename from Problems/3.type/README.md
rename to Challenge/Hongryeol/3.type/README.md
diff --git a/Problems/3.type/solve.js b/Challenge/Hongryeol/3.type/solve.js
similarity index 82%
rename from Problems/3.type/solve.js
rename to Challenge/Hongryeol/3.type/solve.js
index 06ee628..361ebd9 100644
--- a/Problems/3.type/solve.js
+++ b/Challenge/Hongryeol/3.type/solve.js
@@ -8,4 +8,7 @@ console.log(typeof(arr));
 // 1)  undefined
 // 2)  string
 // 3)  number
-// 4)  object
\ No newline at end of file
+// 4)  object
+
+// 정답
+// 4) object
\ No newline at end of file
diff --git a/Problems/4.type(2)/README.md b/Challenge/Hongryeol/4.type(2)/README.md
similarity index 100%
rename from Problems/4.type(2)/README.md
rename to Challenge/Hongryeol/4.type(2)/README.md
diff --git a/Problems/4.type(2)/solve.js b/Challenge/Hongryeol/4.type(2)/solve.js
similarity index 76%
rename from Problems/4.type(2)/solve.js
rename to Challenge/Hongryeol/4.type(2)/solve.js
index 5980544..238fe59 100644
--- a/Problems/4.type(2)/solve.js
+++ b/Challenge/Hongryeol/4.type(2)/solve.js
@@ -5,4 +5,7 @@
 // 1)  입력 : a =1,   출력 : number
 // 2)  입력 : a = 2.22,   출력 : boolean
 // 3)  입력 : a = 'p',   출력 : string
-// 4)  입력 : a = [1, 2, 3],   출력 : object
\ No newline at end of file
+// 4)  입력 : a = [1, 2, 3],   출력 : object
+
+// 정답
+// 2) boolean => number
\ No newline at end of file