Generating a certain amount of random numbers

I'm making a game for an assessment in school and it is to answer a worded version of a number for younger kids (I'm not a younger kid). After a question has been asked if you get it wrong it goes into a list. I need 10 questions on each round and questions wrong in previous rounds are repeated. However if there aren't ten questions then random questions numbers need to be added. I know how to do that but how do I get a specific amount of numbers. Like if you answered 4 wrong so there are 6 spaces how do I generate that amount if I don't know how many are going to be wrong.

PLEASE HELP ME