Structs instead of Classes

//Related to Question at:
//http://groups.google.com/group/dotnetdevelopment/browse_thread/thread/671641a749256799/

public struct EquationSolution
{
  private double[] solns;


  public EquationSolution(double[] solutions)
  {
    solns = (double[])solutions.Clone();
  }


  public int NumberOfSolutions
  {
    get { return solns.Length; }
  }


  public double this[int n]
  {
    get { return solns[n]; }
  }



}


public struct Equation
{
  private double a, b, c;

  public Equation(double a, double b, double c)
  {
    this.a = a; this.b = b; this.c = c;
  }


  public EquationSolution Solve()
  {
    double[] solutions;
    if (a == 0)
      solutions = new double[] { (-c / b) };


    // Get the determinant.
    double d = (b * b) - 4 * a * c;


    if (d < 0)
      solutions = new double[0];  // No real solution.
    else if (d == 0)
      solutions = new double[1] { (-b / (2 * a)) };  // ONE real
solution.
    else // if (d > 0)
      solutions = new double[2] { ((-b + Math.Sqrt(d)) / (2 * a)), ((-
b - Math.Sqrt(d)) / (2 * a)) };  // TWO real solutions.


    return new EquationSolution(solutions);
  }



}


static void Main(string[] args)
{
  string strEndProgram;
  Console.WriteLine("This program solves equation of the form [ax²+bx
+c=0]");
  bool endProgram = false;
  do
  {
    Console.Write("Please enter the value of a:");
    double a = double.Parse(Console.ReadLine());
    Console.Write("Please enter the value of b:");
    double b = double.Parse(Console.ReadLine());
    Console.Write("Please enter the value of c:");
    double c = double.Parse(Console.ReadLine());

    Equation eq = new Equation(a, b, c);
    EquationSolution solutions = eq.Solve();
    switch(solutions.NumberOfSolutions)
    {
      case 0:
        System.Console.WriteLine("No Solution");
        break;
      case 1:
        Console.Out.WriteLine("The Solution is: {0:F1}", solutions
[0]);
        break;
      case 2:
        Console.Out.WriteLine("The Solutions are: {0:F1}, {1:F1}",
solutions[0], solutions[1]);
        break;
    }
    Console.Out.Write("Solve another equation? (y/n)");
    strEndProgram = Console.ReadLine();


    if(strEndProgram.StartsWith("n"))
      endProgram = true;
  } while(!endProgram);


}