有一个分数序列

求出这个数列的前20项之和。

代码1

Private Sub Command1_Click()    Dim sum As Double    Dim a As Integer, b As Integer, t As Integer    a = 1    b = 2    sum = 0    For i = 1 To 20        sum = sum + b / a        t = a + b        a = b        b = t    Next i    Label2.Caption = Str(sum)End Sub

 

代码2

Private Sub Command1_Click()    Dim sum As Double    Dim a As Integer, b As Integer, t As Integer    a = 1    b = 2    sum = b / a    For i = 2 To 20        t = a + b        a = b        b = t	sum = sum + b / a    Next i    Label2.Caption = Str(sum)End Sub