在VB中，编程题

3．有一分数序列2/1，3/2，5/3，8/5，……，求出这个序列的前20项的和。
Dim I As Integer = 0 '循环变量
Dim N As Integer = 2 '分子变量
Dim M As Integer = 1 '分母变量
Dim TempInt As Integer = 0 '临时交换变量
Dim SumInt As Integer = 0 '合计变量
For I = 1 To 20
SumInt = SumInt + N / M
ListBox1.Items.Add(N & "/" & M) '这行用于显示表达式是否正确,和前20个分数(书面答题不要这行)
TempInt = M
M = N
N = N + TempInt
Next I
MsgBox(SumInt) '计算结果40(书面答题不要这行)

4．有一袋球（100到200之间），如果一次数4个，则剩2个；一次数5个，则剩3个；一次数6个，则正好数完，求该袋球的个数。
Dim N As Integer = 0
Dim TempInt As String = ""
For N = 100 To 200
If N Mod 4 = 2 And N Mod 5 = 3 And N Mod 6 = 0 Then
TempInt = TempInt & N & ","
End If
Next N
MsgBox(TempInt) '结果是138和198(书面答题不要这行)

dim i as inter,j as inter,k as inter, l as double
j=2
k=1
l=0
for i=1 to 20
l=l+j/k
j=j+k
k=j-k
next
mess