Public Class Form$1$ Private Sub Button$1\_$Click$()$ Dim T$1$ As Integer Dim num As Integer num $=30$ T$1=0$ Do While num $<=50$ num $=$ num $+10$ T$1=$ T$1+$ num ListBox$1.$AddItem$($num$)$ Loop ListBox$1$AddItem $===================$ ListBox$1.$AddItem$($T$1=$ & T$1)$ End SubEnd Class