Hi Issa

My suggestion would be to have two quizzes with Quiz 2 using the same questions from the question bank as Quiz 1 and allow 1 attempt on both quizzes.

You would make Quiz 2 visible if the first quiz has been failed.

Course completion would be based on the completion of Quiz 1 or Quiz 2

I can't think of how to do this with one quiz - it is possible to have different question behaviours such as Interactive mode and adaptive mode that allows a questions to be tried again but this applies on a question per question basis rather than for a whole quiz.

regards