Create Exam PDF Generator On Website

I have a website on Wordpress. I would some to create an exam generator on it for me. I have images of questions and answers. The idea is that from the admin we upload all the questions and answers I have and say the topic and number of marks. When a user visits the website they will choose the topics they want and the number of marks they want in a paper. The website should automatically create a pdf that is exportable with those questions and another PDF with answers. The user can select multiple topics and the questions will be chosen at random from the all the questions that were uploaded. A previous developer created on my website before and it stopped working and I can't get in touch of him. So there are two options you can fix that one and we improve it or create from scratch.