 <code>
    Public Function Factorial(ByVal factor As Double) As Double
        If factor = 0 Then
            Factorial = 1
        Else
            Factorial = factor * Factorial(factor - 1)
        End If
        Exit Function
        Return (Factorial)
    End Function

    Public Function Permutations(ByVal a As Double, ByVal b As Double) As Double
        Permutations = Factorial(a) / Factorial(a - b)
        Return (Permutations)
    End Function

    Public Function Combinations(ByVal a As Integer, ByVal b As Integer) As Integer
        Combinations = Permutations(a, b) / Factorial(b)
    End Function
</code>