/* Exercise 3.21 Solution */
#include <stdio.h>

void
main ()
{
  float hours, rate, salary;
   
  printf ("Enter number of hours worked (-1 to end): ");
  scanf ("%f", &hours);

  while (hours != -1.0) 
    {
      printf ("Enter hourly rate of the worker ($00.00): ");
      scanf ("%f", &rate);
       
      if (hours <= 40)
        salary = hours * rate;
      else
        salary = 40.0 * rate + (hours - 40.0) * rate * 1.5;

      printf ("Salary is $%.2f\n\n", salary);

      printf ("Enter number of hours worked (-1 to end): ");
      scanf ("%f", &hours);
    }
}