USE OF SUBROUTINES :

Program Code :

/*_____ PROGRAM USING FUNCTION______*/
    int mul (int a, int b);      /*______ DECLARATION______*/
/*_____ MAIN PROGRAM BEGINS________*/
       
main()
{
    int a , b, c;
    a=5;
    b=10;
    c=mul (a,b);

    printf ("multiplication of %d and %d is %d",a,b,c);
}
/*_______ MAIN PROGRAM ENDS       
                  MUL () FUNCTION STRATS _______*/

         int mul (int x, int y)
         int p;
         {
              p=x*y;
              return(p);
         }
 /*______ MUL () FUNCTIONS ENDS ______*/