What is the problem with this code

Question

I don't know what is the problem

https://code.sololearn.com/WR35uYakF4Oo/?ref=app

Answer 1

So what's happening is that the JavaScript code loads first, so it doesn't have access to the elements on the web page. You can do this to prevent an error:
window.onload = function()
{
document.getElementById("hours").innerHTML = calalc(x);
}
This basically runs the code inside it once the window fully loads, including HTML.

Answer 2

https://code.sololearn.com/WR35uYakF4Oo/?ref=app

Answer 3

This is my code 👆🏻👆🏻👆🏻👆🏻👆🏻