c_exercises/1-15.c

#include <stdio.h>
double fahr_to_celsius(int fahr){
  return (5.0/9.0)*(fahr-32);
}
int main(){
  int fahr;
  for (fahr=300; fahr>=0; fahr-=20){
    printf("%3d %6.1f\n", fahr, fahr_to_celsius(fahr));
  }
}