问题说快速货运航运公司收取以下费率：

Weight of Package                                       Rate per 500 Miles Shipped
2 pounds or less                                        $1.10
Over 2 pounds but not more than 6 pounds                $2.20
Over 6 pounds but not more than 10 pounds               $3.70
Over 10 pounds                                          $3.80

每500英里的运费不是按比例计算的。例如，如果一个2磅重的包裹运送了550英里，运费将是2.20美元。编写一个程序，要求用户输入包裹的重量，然后显示运费。
我的问题是，每次输入重量和距离时，我总是收到两个不同的答案。例如，当我输入重量为2磅，距离为500英里时，我得到的答案是$0.0和$3.8，这两个答案都是错误的。看起来我输入的一些重量是正确的答案，而另一些我输入的答案给予错误的。下面是我的程序：

//import java utilities for scanner class
import java.util.Scanner;           

public class ShippingCharge

{

public static void main (String[] args)

{

//Declare and initialize variable to hold the entered weight.
int weight = 0;                                        

//Declare and initialize variable to hold the entered distance.
double distance = 0.0;                                

//This variable will hold the calculated rate.
double rate; 

//This will decide if the shipping charge will advance up one level.
int distanceMultiplier = (int)distance / 500;  

//This will hold the increments of the shipping charge.
int distanceRemainder;                                  

//Create a Scanner object for the input.
Scanner input = new Scanner(System.in);        

//Get the weight of the package.
System.out.println("What is the weight of the package (in pounds)?");

weight = input.nextInt();

//Get the shipping distance of the package.
System.out.println("What is the shipping distance (in miles)?");

distance = input.nextDouble();

distanceRemainder = (int)distance % 500;
if (distanceRemainder == 0)
{
if (weight <= 2)
    System.out.println("Total Shipping Cost is: $" + (distanceMultiplier * 1.10));
    }
else if (weight > 2 && weight <= 6)
{
    System.out.println("Total Shipping Cost is: $" + (distanceMultiplier * 2.20));
    }
else if (weight > 6 && weight <= 10)
{
    System.out.println("Total Shipping Cost is: $" + (distanceMultiplier * 3.70));
    }
else
{
    System.out.println("Total Shipping Cost is: $" + (distanceMultiplier * 3.80));
    }

if (distanceRemainder != 0)
{
    if (weight <= 2)
    System.out.println("Total Shipping Cost is: $" +(distanceMultiplier + 1) * 1.10);
    }
else if (weight > 2 && weight <= 6)
{
    System.out.println("Total Shipping Cost is: $" +(distanceMultiplier + 1) * 2.20);
    }
else if (weight > 6 && weight <= 10)
{

    System.out.println("Total Shipping Cost is: $" +(distanceMultiplier + 1) * 3.70);

    }
else
{
    System.out.println("Total Shipping Cost is: $" +(distanceMultiplier + 1) * 3.80);

    }

 //end program
 System.exit(0);

 }//end main
 }//end class