diff --git a/goawmfhfl/1_8.js b/goawmfhfl/1_8.js
deleted file mode 100644
index 4ff0580..0000000
--- a/goawmfhfl/1_8.js
+++ /dev/null
@@ -1,23 +0,0 @@
-function solution(arr){
-    let answer = [];
-    let sum = 0;
-
-    for(let x of arr){
-        sum+=x
-    }
-
-    for(let i=0; i<arr.length; i++){
-        for(let j=i+1; j<arr.length; j++){
-            if(sum - (arr[i]+arr[j]) === 100){
-                arr.splice(j,1)
-                arr.splice(i,1)
-            }
-        }
-    }
-
-    answer.push(arr)
-    return answer
-}
-
-let arr = [20,7,23,19,10,15,20,8,13]
-console.log(solution(arr));
\ No newline at end of file
diff --git a/goawmfhfl/3_1.js b/goawmfhfl/3_1.js
new file mode 100644
index 0000000..917e26e
--- /dev/null
+++ b/goawmfhfl/3_1.js
@@ -0,0 +1,55 @@
+// 🌟 문제 풀이 🌟
+
+function solution(s){
+    let answer = "NO"
+    const lowerCase = s.toLowerCase()
+
+    for(let i=0; i<s.length; i++){
+        if(lowerCase.indexOf(lowerCase[0]) === lowerCase.indexOf(lowerCase[s.length-1])) answer="YES"
+    }
+    return answer;
+}
+
+console.log(solution("gooG"));
+
+// 🧑🏻‍💻 다른 문제 풀이 🧑🏻‍💻
+
+function solution(s) {
+    const lowerStr = s.toLowerCase();
+    if ([...lowerStr].reverse().join("") === lowerStr) {
+    return "YES";
+    }
+    return "NO";
+    }
+
+    let str = "gooG"
+    console.log(solution(str));
+
+
+// 👨🏻‍🏫 강사님 문제 풀이 1 👨🏻‍🏫
+
+function solution(s){
+    let answer = "YES"
+    s=s.toLowerCase();
+    let len = s.length;
+    for(let i=0; i<Math.floor(len/2); i++){
+        if(s[i]!==s[len-i-1]) return "NO"
+    }
+    return answer;
+}
+
+let str = "gooG"
+console.log(solution(str));
+
+// 👨🏻‍🏫 강사님 문제 풀이 2 👨🏻‍🏫
+
+function solution(s){
+    let answer = "YES"
+    s=s.toLowerCase();
+    if(s.split('').reverse().join('') !== s) return "NO"
+
+    return answer;
+}
+
+let str = "gooG"
+console.log(solution(str));
diff --git a/goawmfhfl/3_2.js b/goawmfhfl/3_2.js
new file mode 100644
index 0000000..4793d96
--- /dev/null
+++ b/goawmfhfl/3_2.js
@@ -0,0 +1,11 @@
+// 👨🏻‍🏫 강사님 문제 풀이 1 👨🏻‍🏫
+
+function solution(s){
+    let answer = "YES";
+    s=s.toLowerCase().replace(/[^a-z]/g,'')
+    if(s.split('').reverse().join('') !== s) return "NO"
+    return answer;
+}
+
+let str ="found7, time:, study, Yduts;, emit, 7Dnuof"
+console.log(solution(str));
diff --git a/goawmfhfl/3_3.js b/goawmfhfl/3_3.js
new file mode 100644
index 0000000..b4a314c
--- /dev/null
+++ b/goawmfhfl/3_3.js
@@ -0,0 +1,27 @@
+// 🌟 문제 풀이 🌟
+
+function solution(arr){
+    let answer = ''
+
+    for(let x of arr){
+        if(!isNaN(x)) answer+=x
+    }   
+    return parseInt(answer);
+}
+
+let str = "g0en2R0s8eSoft"
+console.log(solution(str));
+
+// 👨🏻‍🏫 강사님 문제 풀이 👨🏻‍🏫
+
+function solution(string){
+    let answer = 0;
+
+    for(let x of string){
+        if(!isNaN(x)) answer = answer*10+Number(x);
+        }   
+    return parseInt(answer);
+}
+
+let str = "g0en2R0s8eSoft"
+console.log(solution(str));
\ No newline at end of file
diff --git a/goawmfhfl/3_4.js b/goawmfhfl/3_4.js
new file mode 100644
index 0000000..c713d89
--- /dev/null
+++ b/goawmfhfl/3_4.js
@@ -0,0 +1,36 @@
+// 🌟 문제 풀이 🌟
+
+function solution(s,t){
+    let answer = new Array(s.length).fill(0)
+    let cnt = 1000;
+
+    for(let i=0; i<s.length; i++){
+        if(s[i] === t) {
+            cnt = 0;
+            answer[i] = cnt
+        }
+        else{
+            cnt ++
+            answer[i] = cnt
+        }
+    }
+    console.log(answer);
+
+    cnt = 1000
+
+    for(let i=s.length-1; i>=0; i--){
+        if(s[i] === t){
+            cnt = 0
+            answer[i] = cnt
+        }
+        else{
+            cnt++
+            answer[i]= Math.min(answer[i],cnt)
+        }
+    }
+
+    return answer;
+}
+
+let str = "teachermode"
+console.log(solution(str,'e'));
\ No newline at end of file
diff --git a/goawmfhfl/3_5.js b/goawmfhfl/3_5.js
new file mode 100644
index 0000000..02d89a8
--- /dev/null
+++ b/goawmfhfl/3_5.js
@@ -0,0 +1,19 @@
+// 🌟 문제 풀이 🌟
+
+function solution(s){
+    let answer = [];
+    let cnt = 1;
+
+    for(let i=0; i<s.length; i++){
+        if (s[i]===s[i+1])cnt++
+        else{
+            answer.push(s[i])
+            if(cnt>1) answer.push(String(cnt))
+            cnt = 1
+        }
+    }
+    return answer.join('');
+}
+
+let str = "KKHSSSSSSSE"
+console.log(solution(str));
\ No newline at end of file
diff --git a/goawmfhfl/goawmfhfl.1_14.js b/goawmfhfl/goawmfhfl.1_14.js
deleted file mode 100644
index 2b9f841..0000000
--- a/goawmfhfl/goawmfhfl.1_14.js
+++ /dev/null
@@ -1,14 +0,0 @@
-function solution(a){         
-    let answer= "";
-    let min = Number.MIN_SAFE_INTEGER;
-    for(let x of a){
-        let length = x.length;
-        if(length > min){
-            min = length
-            answer = x
-        }
-    }
-    return answer;
-}
-let arr =["teacher","time","student","beautiful","good"]
-console.log(solution(arr));
\ No newline at end of file
diff --git a/goawmfhfl/goawmfhfl_1_10.js b/goawmfhfl/goawmfhfl_1_10.js
deleted file mode 100644
index c86cbc1..0000000
--- a/goawmfhfl/goawmfhfl_1_10.js
+++ /dev/null
@@ -1,11 +0,0 @@
-function solution(arr,s){
-    let answer = 0;
-
-    for(let x of arr){
-        if(x === s) answer++
-    }
-    return answer;
-}
-let arr = "COMPUTERPROGRAMMING"
-
-console.log(solution(arr,"R"));
\ No newline at end of file
diff --git a/goawmfhfl/goawmfhfl_1_12.js b/goawmfhfl/goawmfhfl_1_12.js
deleted file mode 100644
index 2171054..0000000
--- a/goawmfhfl/goawmfhfl_1_12.js
+++ /dev/null
@@ -1,25 +0,0 @@
-// 첫 번째 문제 풀이
-function solution(a){         
-    let answer= "";
-
-    for(let x of a){
-        if(x === x.toLowerCase()) answer+=x.toUpperCase()
-        else answer+=x
-    }
-    return answer;
-}
-let arr = "itisTimeToStudy"
-console.log(solution(arr));
-
-// 두 번째 문제 풀이
-function solution2(s){
-    let answer = "";
-    for(let x of s){
-        let num = x.charCodeAt()
-        if(num >=97 && num <= 122) answer += String.fromCharCode(num-32);
-        else answer +=x;
-    }
-    return answer;
-}
-let arr2 = "itisTimeToStudy"
-console.log(solution2(arr));
\ No newline at end of file
diff --git a/goawmfhfl/goawmfhfl_1_13.js b/goawmfhfl/goawmfhfl_1_13.js
deleted file mode 100644
index 70777e2..0000000
--- a/goawmfhfl/goawmfhfl_1_13.js
+++ /dev/null
@@ -1,25 +0,0 @@
-
-// 첫 번째 문제 풀이 
-function solution(a){         
-    let answer= "";
-    for(let x of a){
-        let num = x.charCodeAt()
-        if(num>=97 && num<=122) answer+=String.fromCharCode(num-32)
-        else answer+=String.fromCharCode(num+32)
-    }
-    return answer;
-}
-let arr = "StuDY"
-console.log(solution(arr));
-
-// 두 번째 문제 풀이
-function solution(a){         
-    let answer= "";
-    for(let x of a){
-        if(x === x.toUpperCase()) answer+=x.toLowerCase()
-        else answer+=x.toUpperCase()
-    }
-    return answer;
-}
-let arr = "StuDY"
-console.log(solution(arr));
\ No newline at end of file
diff --git a/goawmfhfl/goawmfhfl_1_15.js b/goawmfhfl/goawmfhfl_1_15.js
deleted file mode 100644
index 6779c2c..0000000
--- a/goawmfhfl/goawmfhfl_1_15.js
+++ /dev/null
@@ -1,11 +0,0 @@
-function solution(s){
-    let answer="";
-    let mid = Math.floor(s.length/2)
-
-    if(s.length%2 === 1) answer=s.substring(mid,mid+1)
-    else answer = s.substring(mid-1,mid+1)
-
-    return answer;
-}
-let str = "study"
-console.log(solution(str));
\ No newline at end of file
diff --git a/goawmfhfl/goawmfhfl_1_16.js b/goawmfhfl/goawmfhfl_1_16.js
deleted file mode 100644
index 2c9b110..0000000
--- a/goawmfhfl/goawmfhfl_1_16.js
+++ /dev/null
@@ -1,11 +0,0 @@
-function solution(s){
-    let answer="";
-
-    for(let i=0; i<s.length; i++){
-        if(i===s.indexOf(s[i])) answer+=s[i]
-    }
-    return answer;
-}
-
-let str = "ksekkset"
-console.log(solution(str));
diff --git a/goawmfhfl/goawmfhfl_1_17.js b/goawmfhfl/goawmfhfl_1_17.js
deleted file mode 100644
index 2a82827..0000000
--- a/goawmfhfl/goawmfhfl_1_17.js
+++ /dev/null
@@ -1,25 +0,0 @@
-// indexOf를 활용한 문제 풀이
-
-function solution(s){
-    let answer=[];
-    for(let i=0; i<s.length; i++){
-        if(i === s.indexOf(s[i])) answer.push(s[i])
-    }
-    return answer;
-}
-
-let str = ["good","time","good","time","student"];
-console.log(solution(str));
-
-// filter를 활용한 문제 풀이
-
-function solution(s){
-    let answer;
-    answer = s.filter((v,i)=>{
-        return s.indexOf(v)===i
-    })
-    return answer;
-}
-
-let str = ["good","time","good","time","student"];
-console.log(solution(str));
\ No newline at end of file
diff --git a/goawmfhfl/goawmfhfl_1_9.js b/goawmfhfl/goawmfhfl_1_9.js
deleted file mode 100644
index ddaa903..0000000
--- a/goawmfhfl/goawmfhfl_1_9.js
+++ /dev/null
@@ -1,13 +0,0 @@
-function solution(s){
-    let answer = "";
-
-    for(let x of s){
-        if(x==="A") answer+="#"
-        else answer+= x;
-    }
-
-    return answer;
-}
-
-let str = "BANANA";
-console.log(solution(str));
\ No newline at end of file