C1

#include <stdio.h>

int main()
{
    int fahr;
    float in_celsius(int fahr);
    for ( fahr = 0; fahr <= 300; fahr += 20)
        printf("%3d %6.1f\n", fahr, in_celsius(fahr));
}

float in_celsius(int fahr)
{
    float c;
    c = (5.0/9.0)*(fahr - 32);
    return c;
}