A simple way to provide random order to your Q & A is to use a ListOfPairs of your questions and answers rather than separate Lists for questions and answers.
The example uses an algorithm to shuffle a List (see METRIC RAT AI2 - Shuffling Lists ) by Tim .
Do you have any idea why this part is not working? Theoretically, I should have a sorted list after adding, so that I can delete and modify. Thank you for the previous response.