The formula to find the nth term of the geometric progression is
ar^{n-1} , where a is the first number and r is the common ratio.

In visual basic, we employs the **Do.... Loop Until **statement to generate the numbers in a geometric progression.In this program, we need to insert three text boxes for the user to enter the first number, the common ratio and the number of terms. We also need to insert a list box to list the numbers. Besides that, a command button is need for the user to generate the numbers in the geometric progression.

To add the numbers to the list box, we use the **AddItem** method. The syntax is **List1.AddItem** n, where n can be any variable. The runtime interface is
shown in the figure below.