Simple error in C [closed]

Question

I cannot determine why the Celsius values in this code are producing rubbish values. (Look at second statement in the first for-loop).

CODE:

/* The program will output two columns with the temperature in degrees Fahrenhiet 
and equivalent temperature in degrees Celcius. The range will be 0 to 300 farenhiet in 
20 degree intervals. */

#include <stdio.h>

int main()

{
    double fahr[20], cel[20]; // there should be 16 values (300/20 + 1) in these arrays and a null zero. (total of 17 values)
                              // Doesn't hurt to make them a bit larger than necessary (i.e. 20 instead of 17 values)

    for (int i = 0; i < 16; i++)
    {
            fahr[i] = i*20; // Express Farhrenhiet as a linear function of i and iterate 
            cel[i] = (5 / 9) * (fahr[i] - 32); // Express Celcius as a linear function of fahr[i]
    }

    printf("Fahrenheit\tCelcius\n"); //printing the column headers 

    for (int j = 0; j < 16; j++)
    {
        printf("%.f", fahr[j]);
        printf("\t\t%.2f", cel[j]);
        printf("\n");
    }

    return 0;
}

Answer 1

The expression 5/9 (the second statement of first loop) will make an integer division, which will result in 0. You have to write 5.0/9 or 5/9.0 to get a double value as result.