Dim c As Long
For b = 200 To 400
If InStr(1, b / 3, ".") = 0 And InStr(1, b / 7, ".") <> 0 Then
c = c + 1
End If
Next
MsgBox "200-400之間能被3整除,但不能被7整除的數的個數有" & c & "個"
End Sub