Single Submit Button

I have created a library including a number of problems as a pool of questions. I have added a Randomized Content Block and I have chosen a random number of questions from this library. My problem is that a submit button exists for each question. If my Content block includes 20 questions from the pool, the user will need to press 20 different submit buttons for each question! Does anybody know how can I have a single submit button for the whole quiz? Does anybody know an alternative solution (eg x-block0 to implement a random quiz from a pool of questions and submit the whole quiz with a single button?

every question is a saparate intractive and having their own submit button. I guess, it is not possible with existing intractive xblocks.

Thank you for your reply. Do you know any alternative to create a random test with a single submit button?