I am new to coding and I some advice with coding a math equation (multiplaction)using RandomObject.Next

This my statements:

Module MathQuiz
Sub Main()
'create random Mathequation
Dim randomObject As New Random()
Dim randomNumber As Integer = randomObject.Next() 'generate random number
Dim j As Integer
Dim k As Integer

'generate 20 random numbers between 1 and 15
For j As Integer = 1 To 15

Next
Console.Write()

For k As Integer = 1 To 15
Console.Write("randomObject.Next, k = 7")

If j And k Mod 15 = 0 Then

Console.WriteLine()
Console.ReadLine()

End If
Next

End Sub

End Module 'MathQuiz