How to write program that 'Convert Fahrenheit to Kelvin' ?

Question

Write a program to convert a temperature in degrees Fahrenheit to the kelvin scale.

Data Requirements

Problem Input

 int fahrenheit /* temperature in degrees Fahrenheit    */

Problem Output

 double kelvin /* temperature on the kelvin scale       */

Relevant Formula

kelvin = 5/9 (fahrenheit − 32) + 273.15

Answer 1

double FtoK(int f) {
return ((double)f-32.0)*5.0/9.0+273.15;
}

Answer 2

That's a function, which can be called in the following way:
http://code.sololearn.com/clUd0UKVfsjE/#

#include <iostream>
using namespace std;

double convertToKelvin(double f) {
return (f - 32) * 5 / 9 + 273.15;
}

int main()
{
double fahrenheit = 22.32;
double result = convertToKelvin(fahrenheit);
cout << fahrenheit << " fahrenheit = " << result << " kelvin." << endl;
return 0;
}

Answer 3

this doesn't make sense much