diff --git a/README.md b/README.md
index 2b5538a..d3af9be 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
+[![Review Assignment Due Date](https://classroom.github.com/assets/deadline-readme-button-22041afd0340ce965d47ae6ef1cefeee28c7c493a6346c4f15d667ab976d596c.svg)](https://classroom.github.com/a/LBh0h0yx)
 # Assignment 1: C Programming Basics
 
 ## Instructions
diff --git a/src/q1.c b/src/q1.c
index e9adc59..04a3465 100644
--- a/src/q1.c
+++ b/src/q1.c
@@ -1,6 +1,15 @@
-/* Write a C program that takes an integer input from the user and determines if it is positive, negative, or zero.
-Expected Output:
-If n > 0, print Positive (case-insensitive, extra messages allowed).
-If n < 0, print Negative (case-insensitive, extra messages allowed).
-If n == 0, print Zero (case-insensitive, extra messages allowed).
-*/
\ No newline at end of file
+#include <stdio.h>
+int main() {
+    int n;
+    printf("Enter an integer: ");
+    scanf("%d", &n);
+
+    if (n > 0)
+        printf("The number is Positive.\n");
+    else if (n < 0)
+        printf("The number is Negative.\n");
+    else
+        printf("The number is Zero.\n");
+
+    return 0;
+}
diff --git a/src/q10.c b/src/q10.c
index 05a3fd8..2d12955 100644
--- a/src/q10.c
+++ b/src/q10.c
@@ -1,5 +1,18 @@
-/* Write a C program that prints a pattern of asterisks.
-      *
-     ***
-    *****
-*/
\ No newline at end of file
+#include <stdio.h>
+
+int main() {
+    int i, j, k;
+    int n = 3;
+
+    for(i = 1; i <= n; i++) {
+        for(j = 1; j <= n - i; j++) {
+            printf(" ");
+        }
+        for(k = 1; k <= 2*i - 1; k++) {
+            printf("*");
+        }
+        printf("\n");
+    }
+
+    return 0;
+}
diff --git a/src/q11.c b/src/q11.c
index 30824f6..ca9816e 100644
--- a/src/q11.c
+++ b/src/q11.c
@@ -1,5 +1,18 @@
-/* Write a C program that prints a pattern of asterisks.
-    *****
-     ***
-      *
-*/
\ No newline at end of file
+#include <stdio.h>
+
+int main() {
+    int i, j, k;
+    int n = 3;
+
+    for(i = n; i >= 1; i--) {
+        for(j = 1; j <= n - i; j++) {
+            printf(" ");
+        }
+        for(k = 1; k <= 2*i - 1; k++) {
+            printf("*");
+        }
+        printf("\n");
+    }
+
+    return 0;
+}
diff --git a/src/q12.c b/src/q12.c
index ac47268..0047a8e 100644
--- a/src/q12.c
+++ b/src/q12.c
@@ -1 +1,11 @@
-// Write a C program that prints all numbers from 1 to 100 using a for loop.
\ No newline at end of file
+#include <stdio.h>
+
+int main() {
+    int i;
+
+    for(i = 1; i <= 100; i++) {
+        printf("%d\n", i);
+    }
+
+    return 0;
+}
diff --git a/src/q13.c b/src/q13.c
index 8009d54..a23ab4f 100644
--- a/src/q13.c
+++ b/src/q13.c
@@ -1 +1,10 @@
-// Write a C program that calculates the sum of all even numbers from 1 to 50 using a while loop.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int i=2,sum=0;
+    while(i<=50){
+        sum+=i;
+        i+=2;
+    }
+    printf("%d\n",sum);
+    return 0;
+}
diff --git a/src/q14.c b/src/q14.c
index 8f1a9d5..76834ae 100644
--- a/src/q14.c
+++ b/src/q14.c
@@ -1 +1,16 @@
-// Write a C program that prompts the user for a positive integer and prints all the factors of that number using a for loop.
\ No newline at end of file
+#include <stdio.h>
+int main() {
+int num, i;
+
+    printf("Enter a positive integer: ");
+    scanf("%d", &num);
+
+    printf("Factors of %d are:\n", num);
+    for(i = 1; i <= num; i++) {
+        if(num % i == 0) {
+            printf("%d\n", i);
+        }
+    }
+
+    return 0;
+}
diff --git a/src/q15.c b/src/q15.c
index f582057..8316680 100644
--- a/src/q15.c
+++ b/src/q15.c
@@ -1 +1,27 @@
-// Write a C program that prompts the user for a positive integer and checks if it is a prime number using a while loop.
\ No newline at end of file
+#include <stdio.h>
+
+int main() {
+    int num, i = 2, isPrime = 1;
+
+    printf("Enter a positive integer: ");
+    scanf("%d", &num);
+
+    if(num <= 1) {
+        isPrime = 0;
+    }
+
+    while(i < num) {
+        if(num % i == 0) {
+            isPrime = 0;
+            break;
+        }
+        i++;
+    }
+
+    if(isPrime)
+        printf("%d is a prime number.\n", num);
+    else
+        printf("%d is not a prime number.\n", num);
+
+    return 0;
+}
diff --git a/src/q16.c b/src/q16.c
index af07832..9e51329 100644
--- a/src/q16.c
+++ b/src/q16.c
@@ -1 +1,18 @@
-// Write a C program that calculates the factorial of a given number using a do-while loop.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int num,i;
+    unsigned long long factorial=1;
+    printf("Enter a positive integer: ");
+    scanf("%d",&num);
+    i=1;
+    if(num<0){
+        printf("Factorial is not defined for negative numbers.\n");
+    }else{
+        do{
+            factorial*=i;
+            i++;
+        }while(i<=num);
+        printf("Factorial of %d is %llu\n",num,factorial);
+    }
+    return 0;
+}
diff --git a/src/q17.c b/src/q17.c
index 6858adf..4fe43bf 100644
--- a/src/q17.c
+++ b/src/q17.c
@@ -1 +1,10 @@
-// Write a C program that prompts the user for a positive integer and prints a countdown from that number to 1 using a for loop.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int num,i;
+    printf("Enter a positive integer: ");
+    scanf("%d",&num);
+    for(i=num;i>=1;i--){
+        printf("%d\n",i);
+    }
+    return 0;
+}
diff --git a/src/q18.c b/src/q18.c
index 4229091..1201b38 100644
--- a/src/q18.c
+++ b/src/q18.c
@@ -1,2 +1,11 @@
-// Write a C program that prompts the user for a positive integer and prints the
-// multiplication table for that number up to 10 using a while loop.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int num,i=1;
+    printf("Enter a positive integer: ");
+    scanf("%d",&num);
+    while(i<=10){
+        printf("%d x %d = %d\n",num,i,num*i);
+        i++;
+    }
+    return 0;
+}
diff --git a/src/q19.c b/src/q19.c
index a2b2ae3..0b0b721 100644
--- a/src/q19.c
+++ b/src/q19.c
@@ -1,5 +1,13 @@
-/* Write a C program that prompts the user for a positive integer and prints a pattern of asterisks (*) in a square shape using nested loops.
-Example: User’s Input = 2, then pattern to print will be:
-    * *
-    * *
-*/
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int n,i,j;
+    printf("Enter a positive integer: ");
+    scanf("%d",&n);
+    for(i=1;i<=n;i++){
+        for(j=1;j<=n;j++){
+            printf("* ");
+        }
+        printf("\n");
+    }
+    return 0;
+}
diff --git a/src/q2.c b/src/q2.c
index 30e6fa0..9b192e0 100644
--- a/src/q2.c
+++ b/src/q2.c
@@ -1,5 +1,13 @@
-/* Write a C program that prompts the user for their age and determines if they are eligible to vote (consider the legal voting age in your country).
-Expected Output:
-If age >= 18, print Eligible to vote (case-insensitive, extra messages allowed).
-If age < 18, print Not eligible to vote (case-insensitive, extra messages allowed).
-*/
\ No newline at end of file
+#include <stdio.h>
+int main() {
+    int age;
+    printf("Enter your age: ");
+    scanf("%d", &age);
+
+    if (age >= 18)
+        printf("Eligible to vote.\n");
+    else
+        printf("Not eligible to vote.\n");
+
+    return 0;
+}
diff --git a/src/q20.c b/src/q20.c
index 8d1027a..c909a52 100644
--- a/src/q20.c
+++ b/src/q20.c
@@ -1 +1,17 @@
-// Write a C program that prompts the user for a number between 1 and 7 and prints the corresponding day of the week using a switch-case statement.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int day;
+    printf("Enter a number between 1 and 7: ");
+    scanf("%d",&day);
+    switch(day){
+        case 1: printf("Sunday\n"); break;
+        case 2: printf("Monday\n"); break;
+        case 3: printf("Tuesday\n"); break;
+        case 4: printf("Wednesday\n"); break;
+        case 5: printf("Thursday\n"); break;
+        case 6: printf("Friday\n"); break;
+        case 7: printf("Saturday\n"); break;
+        default: printf("Invalid input\n");
+    }
+    return 0;
+}
diff --git a/src/q3.c b/src/q3.c
index f74a4ac..39bbca8 100644
--- a/src/q3.c
+++ b/src/q3.c
@@ -1 +1,12 @@
-// Write a C program that calculates the absolute value of a given number without using the built-in absolute value function.
\ No newline at end of file
+#include <stdio.h>
+int main() {
+    int n;
+    printf("Enter a number: ");
+    scanf("%d", &n);
+
+    if (n < 0)
+        n = -n;
+
+    printf("Absolute value: %d\n", n);
+    return 0;
+}
diff --git a/src/q4.c b/src/q4.c
index 35772e9..47d06ee 100644
--- a/src/q4.c
+++ b/src/q4.c
@@ -1 +1,8 @@
-// Write a C program that prints all even numbers between 1 and 100 using a for loop.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int i;
+    for(i=2;i<=100;i+=2){
+        printf("%d ",i);
+    }
+    return 0;
+}
diff --git a/src/q5.c b/src/q5.c
index f89ed1d..286532b 100644
--- a/src/q5.c
+++ b/src/q5.c
@@ -1 +1,12 @@
-// Write a C program that prompts the user for a positive integer and calculates the factorial of that number using a while loop.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int n,i=1;
+    unsigned long long f=1;
+    scanf("%d",&n);
+    while(i<=n){
+        f*=i;
+        i++;
+    }
+    printf("%llu\n",f);
+    return 0;
+}
diff --git a/src/q6.c b/src/q6.c
index 6b94dca..83ddbed 100644
--- a/src/q6.c
+++ b/src/q6.c
@@ -1 +1,10 @@
-// Write a C program that prompts the user for a number and prints its multiplication table up to 10 using a do-while loop.
\ No newline at end of file
+#include <stdio.h>
+int main(){
+    int num,i=1;
+    scanf("%d",&num);
+    do{
+        printf("%d x %d = %d\n",num,i,num*i);
+        i++;
+    }while(i<=10);
+    return 0;
+}
diff --git a/src/q7.c b/src/q7.c
index 3678e6f..d5afe42 100644
--- a/src/q7.c
+++ b/src/q7.c
@@ -1,11 +1,19 @@
-/* Write a C program that prints a pattern of asterisks.
-    *
-    **
-    ***
-    ****
-    *****
-    ****
-    ***
-    **
-    *
-*/
\ No newline at end of file
+#include <stdio.h>
+
+int main() {
+    int i, j;
+    int n = 5;
+for(i = 1; i <= n; i++) {
+        for(j = 1; j <= i; j++) {
+            printf("*");
+        }
+        printf("\n");
+    }
+for(i = n-1; i >= 1; i--) {
+        for(j = 1; j <= i; j++) {
+            printf("*");
+        }
+        printf("\n");
+    }
+return 0;
+}
diff --git a/src/q8.c b/src/q8.c
index d9575f4..27a8031 100644
--- a/src/q8.c
+++ b/src/q8.c
@@ -1,7 +1,15 @@
-/* Write a C program that prints a pattern of asterisks.
-    *
-    **
-    ***
-    ****
-    *****
-*/
\ No newline at end of file
+#include <stdio.h>
+
+int main() {
+    int i, j;
+    int n = 5;
+
+    for(i = 1; i <= n; i++) {
+        for(j = 1; j <= i; j++) {
+            printf("*");
+        }
+        printf("\n");
+    }
+
+    return 0;
+}
diff --git a/src/q9.c b/src/q9.c
index f4f89d0..e9cca37 100644
--- a/src/q9.c
+++ b/src/q9.c
@@ -1,7 +1,15 @@
-/* Write a C program that prints a pattern of asterisks.
-    *****
-    ****
-    ***
-    **
-    *
-*/
\ No newline at end of file
+#include <stdio.h>
+
+int main() {
+    int i, j;
+    int n = 5;
+
+    for(i = n; i >= 1; i--) {
+        for(j = 1; j <= i; j++) {
+            printf("*");
+        }
+        printf("\n");
+    }
+
+    return 0;
+}