There is a error in the below program. Which statement will you add to remove it

There is a error in the below program. Which statement will you add to remove it?

#include<stdio.h>
int main()
 {
     int a;
     a = f(10, 3.14);
     printf("%d\n", a);
     return 0;
 }
 float f(int aa, float bb)
 {
     return ((float)aa + bb);
 }

2) Point out the error in the program

   f(int a, int b)
 {
     int a;
     a = 20;
     return a;
 }

					  

3) What will be the output of the program?

#include<stdio.h>
int i;
int fun();
int main()
 {
     while(i)
     {
         fun();
         main();
     }
     printf("Hello\n");
     return 0;
 }
 int fun()
 {
     printf("Hi");
 }

4) What will be the output of the program?

#include<stdio.h>
int addmult(int ii, int jj)
 {
     int kk, ll;
     kk = ii + jj;
     ll = ii * jj;
     return (kk, ll);
 }
int main()
 {
     int i=3, j=4, k, l;
     k = addmult(i, j);
     l = addmult(i, j);
     printf("%d %d\n", k, l);
     return 0;
 }

5) Which of the following is not a library function: