Paint Costs Code Coach, Why does this work?[SOLVED]

Question

In my first program the variable "total" was an "int" and it failed tests 3 and 4. On changing it to "double", for some reason it passed all of the tests. My question is why? What difference did it make on changing the data type?

My both tries:
https://code.sololearn.com/cQzrf8NChi8G/?ref=app
https://code.sololearn.com/cVIZLukuS9Zz/?ref=app

Answer 1

Dividing an integer by an integer results in an integer.
Check, this will give the desired result:
int total = 40+(paintsNo*5);
double tax = 10.0*total/100;

System.out.println(
Math.round(total+tax)
);

Answer 2

Solo thank you