Paint Cost Tax [solved]

Question

Can someone explain why I had to use tax = 0.1 in this exercise instead of using tax = 10 and then dividing the total cost * tax by a hundred? Because the second wouldn't solve for case 3 and 4...

here's my code, FYI

static void Main(string[] args)
{
int nOC = Convert.ToInt32(Console.ReadLine());

const double tax =0.1;
const int pC = 5;
const int pB = 40;

double totC = pB + pC * nOC;
double taxP = totC *tax ;

double output = Math.Round (taxP+totC);
Console.WriteLine(Convert.ToInt32(output));
}

Answer 1

Each way is good if you use a double for tax.

Answer 2

Ha, before, when tax was still 10, it was an int, so that was the problem. Thank you.