What will be the output of the program?

#include<stdio.h>

int main()
{
    enum status {pass, fail, absent};
    enum status stud1, stud2, stud3;
    stud1 = pass;
    stud2 = absent;
    stud3 = fail;
    printf("%d %d %d\n", stud1, stud2, stud3);
    return 0;
}

#include<stdio.h>
int main()
{
    int i=2;
    printf("%d, %d\n", ++i, ++i);
    return 0;
}

#include<stdio.h>
#include<stdlib.h>

int main()
{
    char *i = "55.555";
    int result1 = 10;
    float result2 = 11.111;
    result1 = result1+atoi(i);
    result2 = result2+atof(i);
    printf("%d, %f", result1, result2);
    return 0;
}

#include<stdio.h>
const char *fun();

int main()
{
    char *ptr = fun();
    return 0;
}
const char *fun()
{
    return "Hello";
}

#include<stdio.h>
#include<stdarg.h>

int main()
{
    void display(char *s, int num1, int num2, ...);
    display("Hello", 4, 2, 12.5, 13.5, 14.5, 44.0);
    return 0;
}
void display(char *s, int num1, int num2, ...)
{
    double c;
    char s;
    va_list ptr;
    va_start(ptr, s);
    c = va_arg(ptr, double);
    printf("%f", c);
}

#include<stdio.h>
#include<stdarg.h>
void display(int num, ...);

int main()
{
    display(4, 'A', 'a', 'b', 'c');
    return 0;
}
void display(int num, ...)
{
    char c; int j;
    va_list ptr;
    va_start(ptr, num);
    for(j=1; j<=num; j++)
    {
        c = va_arg(ptr, char);
        printf("%c", c);
    }
}

#include<stdio.h>
#include<stdarg.h>
void varfun(int n, ...);

int main()
{
    varfun(3, 7, -11, 0);
    return 0;
}
void varfun(int n, ...)
{
    va_list ptr;
    int num;
    num = va_arg(ptr, int);
    printf("%d", num);
}