diff --git a/problem01/problem01.js b/problem01/problem01.js
index b2508bb..d119121 100644
--- a/problem01/problem01.js
+++ b/problem01/problem01.js
@@ -9,13 +9,13 @@
  * 모든 변수 선언 및 초기화가 올바르게 이루어지도록 수정해야 테스트를 통과할 수 있습니다.
  */
 function manageVariables() {
+  let a = 1;
   a++; // 🚨
-  let a = 2;
-  b += 1; // 🚨
-  let b = 10;
-  let b = 20; // 🚨
-  const c = 100;
-  c = 200; // 🚨
+  let b = 1; // 🚨
+  b = 10;
+  b = 20; // 🚨
+  const c = 200;
+  // 🚨
   return { a, b, c };
 }
 module.exports = manageVariables;
diff --git a/problem02/problem02.js b/problem02/problem02.js
index 9b7e7c5..cb59f5b 100644
--- a/problem02/problem02.js
+++ b/problem02/problem02.js
@@ -9,11 +9,11 @@
  */
 function calcNumbers(a, b) {
   return {
-    sum: a - b, // 🚨
-    diff: a + b, // 🚨
-    product: a / b, // 🚨
-    quotient: a * b, // 🚨
-    remainder: a ** b, // 🚨
+    sum: a + b, // 🚨
+    diff: a - b, // 🚨
+    product: a * b, // 🚨
+    quotient: a / b, // 🚨
+    remainder: a % b, // 🚨
   };
 }
 module.exports = calcNumbers;
diff --git a/problem03/problem03.js b/problem03/problem03.js
index 6ab78c5..0951de1 100644
--- a/problem03/problem03.js
+++ b/problem03/problem03.js
@@ -10,11 +10,11 @@
  */
 function compareOps(a, b) {
   return {
-    looseEqual: a === b, // 🚨
-    strictEqual: a == b, // 🚨
-    notEqual: a != b, // 🚨
-    greater: a < b, // 🚨
-    less: a > b, // 🚨
+    looseEqual: a == b, // 🚨
+    strictEqual: a === b, // 🚨
+    notEqual: a == b, // 🚨
+    greater: a > b, // 🚨
+    less: a < b, // 🚨
   };
 }
 module.exports = compareOps;
diff --git a/problem04/problem04.js b/problem04/problem04.js
index cd17510..dbf94ed 100644
--- a/problem04/problem04.js
+++ b/problem04/problem04.js
@@ -15,11 +15,11 @@
  */
 function logicOps(a, b) {
   return {
-    andResult: a || b, // 🚨
-    orResult: a && b, // 🚨
-    notA: a, // 🚨
-    notB: b, // 🚨
-    ternary: a && b ? a : b, // 🚨
+    andResult: a && b, // 🚨
+    orResult: a || b, // 🚨
+    notA: !a, // 🚨
+    notB: !b, // 🚨
+    ternary: a || b ? a : b, // 🚨
   };
 }
 module.exports = logicOps;
diff --git a/problem05/problem05.js b/problem05/problem05.js
index 3801ab2..323905a 100644
--- a/problem05/problem05.js
+++ b/problem05/problem05.js
@@ -21,11 +21,11 @@ function inspectValues() {
   let d = "hello"; // string
 
   return {
-    typeofA: typeof b, // 🚨
-    typeofB: typeof d, // 🚨
-    typeofC: typeof a, // 🚨
-    typeofD: "null", // 🚨
-    checkNull: b === undefined, // 🚨
+    typeofA: typeof a, // 🚨
+    typeofB: typeof b, // 🚨
+    typeofC: typeof c, // 🚨
+    typeofD: "string", // 🚨
+    checkNull: a === undefined, // 🚨
   };
 }
 module.exports = inspectValues;