ModulEkz/Calculation/Calculator.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Calculation
{
    public class Calculator
    {
        public int Calc(decimal price, int count)
        {
            int sale = 0;
            if (count > 0 && price > 0)
            {
                if (count >= 3)
                {
                    sale = 5;
                }
                if (count >= 5)
                {
                    sale = 10;
                }
                if (count >= 10)
                {
                    sale = 15;
                }
                if (price / 500 >= 1)
                {
                    sale += Convert.ToInt32(Math.Floor(price / 500));
                }
            }
            return sale;
        }
    }
}