diff --git a/Ishita_q1.c b/Ishita_q1.c
new file mode 100644
index 0000000..3a92e0b
--- /dev/null
+++ b/Ishita_q1.c
@@ -0,0 +1,11 @@
+#include <iostream>
+using namespace std;
+
+int main()
+{
+    int num = -15;
+        
+    if(num == 0){
+        cout << "Zero";
+    }else (num > 0) ? cout << "Positive": cout << "Negative";
+}
diff --git a/Ishita_q10.c b/Ishita_q10.c
new file mode 100644
index 0000000..a6c2e89
--- /dev/null
+++ b/Ishita_q10.c
@@ -0,0 +1,28 @@
+#include <iostream>
+#include<math.h>
+using namespace std;
+
+bool checkPrime(int n){
+    if(n<2){
+        return false;
+    }else{
+        for(int i=2;i<sqrt(n);i++){
+            if(n%i == 0){
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+int main() {
+    int st,end;
+    cout<<"Enter start and end of range: ";
+    cin>>st>>end;
+    for(int i=st;i<=end;i++){
+        if(checkPrime(i)){
+            cout<<i<<" ";
+        }
+    }
+    return 0;
+}
diff --git a/Ishita_q11.c b/Ishita_q11.c
new file mode 100644
index 0000000..dbcad77
--- /dev/null
+++ b/Ishita_q11.c
@@ -0,0 +1,18 @@
+#include<iostream>
+using namespace std;
+
+int getSum(int num, int sum){
+    if(num==0) return sum;
+    sum+=(num%10);
+    return getSum(num/10,sum);
+}
+
+int main ()
+{
+    int num, sum = 0;
+    cout<<"Enter number: ";
+    cin>>num;
+    cout <<"Sum of digits : " << getSum(num, sum);
+ 
+    return 0;
+}
diff --git a/Ishita_q12.c b/Ishita_q12.c
new file mode 100644
index 0000000..88950de
--- /dev/null
+++ b/Ishita_q12.c
@@ -0,0 +1,36 @@
+#include <iostream>
+#include <string.h>
+using namespace std;
+
+void lower(char str[]){
+  int i = 0;
+  while (str[i] != '\0'){
+    str[i] = tolower(str[i]);
+    i++;
+  }
+}
+int main() 
+{
+    string str;
+    cin>>str;
+    int i, len, flag = 0;
+    
+    lower(str);
+    
+    len = strlen(str);
+    
+    for (i = 0; i < len / 2; i++) 
+    {
+        if (str[i] != str[len - i - 1]){
+            flag++;
+            break;
+        }
+    }
+
+    if (flag)
+        cout << str << " is not palindrome";
+    else
+        cout << str << " is palindrome";
+        
+    return 0;
+}
diff --git a/Ishita_q13.c b/Ishita_q13.c
new file mode 100644
index 0000000..ce87e61
--- /dev/null
+++ b/Ishita_q13.c
@@ -0,0 +1,40 @@
+#include<bits/stdc++.h> 
+#include<math.h> 
+using namespace std;
+
+int power(int x){
+    int len = 0;
+    while (x){
+        len++;
+        x = x/10;
+    }
+    return len;
+}
+
+void armstrong(int st,int end){
+    
+    for(int num = st; num <= end; num++){
+        
+        int sum = 0, temp, len;
+        temp = num;
+        
+        len = power(num);
+        
+        while(temp != 0){
+            int digit = temp % 10;
+            sum = sum + pow(digit,len);;
+            temp /= 10;
+        };
+    
+        if(sum == num) cout << num << " ";
+    }
+}
+
+int main (){
+    int st,end;
+    cout<<"Enter ranges:";
+    cin>>st>>end;
+    armstrong(st,end);
+
+    return 0;
+}
diff --git a/Ishita_q14.c b/Ishita_q14.c
new file mode 100644
index 0000000..9ef9bc9
--- /dev/null
+++ b/Ishita_q14.c
@@ -0,0 +1,17 @@
+#include<bits/stdc++.h>
+using namespace std;
+ 
+int fibo(int num){
+    if (num <= 1){
+        return num;
+     }
+    return fibo(num-1) + fibo(num-2);
+}
+ 
+int main (){
+    int n;
+    cout<<"Enter num: ";
+    cin>>n;
+    for(int i = 0; i < n; i++)
+        cout << fibo(i) << ", ";
+}
diff --git a/Ishita_q15.c b/Ishita_q15.c
new file mode 100644
index 0000000..0357ac5
--- /dev/null
+++ b/Ishita_q15.c
@@ -0,0 +1,18 @@
+#include<bits/stdc++.h>
+using namespace std;
+ 
+int fibo(int num){
+    if (num <= 1){
+        return num;
+     }
+    return fibo(num-1) + fibo(num-2);
+ 
+}
+ 
+int main (){
+    int n;
+    cout<<"Enter num: ";
+    cin>>n;
+    cout << fibo(n);
+    return 0;
+}
diff --git a/Ishita_q16.java b/Ishita_q16.java
new file mode 100644
index 0000000..14788bd
--- /dev/null
+++ b/Ishita_q16.java
@@ -0,0 +1,17 @@
+import java.util.Scanner;
+
+public class Main {
+    
+    static int fact(int num){
+        if(num==0){
+            return 1;
+        }
+        return num*fact(num-1);
+    }
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int a = sc.nextInt();
+        int fct = fact(a);
+        System.out.println("Fact: "+fct);
+    }
+}
diff --git a/Ishita_q17.java b/Ishita_q17.java
new file mode 100644
index 0000000..03e9ad2
--- /dev/null
+++ b/Ishita_q17.java
@@ -0,0 +1,12 @@
+import java.util.Scanner;
+
+public class Main {
+  
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int base = sc.nextInt();
+        double exp = sc.nextDouble();
+        double res1 = Math.pow(base, exp);
+ 	    System.out.println(base + " ^ " + exp + " = " + res1 );
+    }
+}
diff --git a/Ishita_q18.java b/Ishita_q18.java
new file mode 100644
index 0000000..e546298
--- /dev/null
+++ b/Ishita_q18.java
@@ -0,0 +1,25 @@
+import java.util.Scanner;
+
+class Main{
+
+    static void getFact(int n)
+    {
+        for(int i = 1; i <= Math.sqrt(n); ++i)
+        {
+            if (n % i == 0){
+                if(i == n / i)
+                    System.out.print(i + ", ");
+                else
+                    System.out.print(i + ", " + n/i + ", ");
+            }
+        }
+    }
+
+    public static void main(String[] args){
+        
+        Scanner sc = new Scanner(System.in);
+        int a = sc.nextInt();
+        getFact(a);
+    }
+
+}
diff --git a/Ishita_q19.java b/Ishita_q19.java
new file mode 100644
index 0000000..6cd885c
--- /dev/null
+++ b/Ishita_q19.java
@@ -0,0 +1,26 @@
+import java.util.Scanner;
+
+class Main {
+    static void getPrimeF(int n) {
+        while (n % 2 == 0) {
+            System.out.print(2 + "  ");
+            n /= 2;
+        }
+
+        for (int i = 3; i <= Math.sqrt(n); i += 2) {
+            while (n % i == 0) {
+                System.out.print(i + " ");
+                n /= i;
+            }
+        }
+        if (n > 2) {
+            System.out.print(n);
+        }
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int a = sc.nextInt();
+        getPrimeF(a); 
+    }
+}
diff --git a/Ishita_q2.c b/Ishita_q2.c
new file mode 100644
index 0000000..bc03658
--- /dev/null
+++ b/Ishita_q2.c
@@ -0,0 +1,10 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+    int n;
+    cout<<"Enter num: ";
+    cin>>n;
+    (n%2==0) ? cout<<"Even":cout<<"Odd";
+    return 0;
+}
diff --git a/Ishita_q20.java b/Ishita_q20.java
new file mode 100644
index 0000000..7f92036
--- /dev/null
+++ b/Ishita_q20.java
@@ -0,0 +1,34 @@
+import java.util.Scanner;
+
+class Main {
+    static int fact(int num){
+        if(num == 0){
+            return 1;
+        }
+        return num * fact(num-1);
+    }
+    static boolean detectStrong (int num)
+  {
+
+     int digit, sum = 0;
+    int temp = num;
+    
+    while(temp!=0){
+        digit = temp % 10;
+        
+        sum = sum + fact(digit);
+        temp /= 10;
+    }
+    
+    return sum == num;
+
+  }
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int num =sc.nextInt();
+        if (detectStrong(num))
+        System.out.println (num + " is Strong Number");
+        else
+        System.out.println (num + " is not a Strong Number");
+    }
+}
diff --git a/Ishita_q3.c b/Ishita_q3.c
new file mode 100644
index 0000000..7b8146a
--- /dev/null
+++ b/Ishita_q3.c
@@ -0,0 +1,13 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+    int n;
+    cout<<"Enter num: ";
+    cin>>n;
+    int sum=n*(n+1)/2;
+    cout<<"Sum: "<<sum;
+    return 0;
+}
+
+// Ques 3 and 4 can have the same codes
diff --git a/Ishita_q5.c b/Ishita_q5.c
new file mode 100644
index 0000000..1ba00c6
--- /dev/null
+++ b/Ishita_q5.c
@@ -0,0 +1,18 @@
+#include <iostream>
+using namespace std;
+
+int calcSum(int a,int b){
+    if(b<a){
+        return 0;
+    }
+    return b+calcSum(a,b-1);
+}
+
+int main() {
+    int a,b;
+    cout<<"Enter num: ";
+    cin>>a>>b;
+    int sum=calcSum(a,b);
+    cout<<sum;
+    return 0;
+}
diff --git a/Ishita_q6.c b/Ishita_q6.c
new file mode 100644
index 0000000..23ddf26
--- /dev/null
+++ b/Ishita_q6.c
@@ -0,0 +1,12 @@
+#include <iostream>
+#include<math.h>
+using namespace std;
+
+int main() {
+    int a,b;
+    cout<<"Enter num: ";
+    cin>>a>>b;
+    int largest = max(a,b);
+    cout<<largest;
+    return 0;
+}
diff --git a/Ishita_q7.c b/Ishita_q7.c
new file mode 100644
index 0000000..7e50711
--- /dev/null
+++ b/Ishita_q7.c
@@ -0,0 +1,12 @@
+#include <iostream>
+#include<math.h>
+using namespace std;
+
+int main() {
+    int a,b,c;
+    cout<<"Enter num: ";
+    cin>>a>>b>>c;
+    int largest = max(a,max(b,c));
+    cout<<"Largest num: "<<largest;
+    return 0;
+}
diff --git a/Ishita_q8.c b/Ishita_q8.c
new file mode 100644
index 0000000..cf9f038
--- /dev/null
+++ b/Ishita_q8.c
@@ -0,0 +1,11 @@
+#include <iostream>
+#include<math.h>
+using namespace std;
+
+int main() {
+    int year;
+    cout<<"Enter num: ";
+    cin>>year;
+    (year%400 == 0 || (year%4==0 && year%100!=0)) ? cout<<"Leap year" : cout<<"Not leap year";
+    return 0;
+}
diff --git a/Ishita_q9.c b/Ishita_q9.c
new file mode 100644
index 0000000..cd41645
--- /dev/null
+++ b/Ishita_q9.c
@@ -0,0 +1,23 @@
+#include <iostream>
+#include<math.h>
+using namespace std;
+
+int main() {
+    int i,n;
+    cout<<"Enter num: ";
+    cin>>n;
+    bool check = true;
+    if(n<2){
+        check = false;
+    }else{
+        for(int i=2;i<sqrt(n);i++){
+            if(n%i == 0){
+                check = false;
+                break;
+            }
+        }
+    }
+    
+    check ? cout<<"Prime":cout<<"Not prime";
+    return 0;
+}