How hard is the test? Do the questions get repeated in each attempt?

Also, before we take the test, one of the instructions say that there are 30 marks for a project video. What is that all about? Where must this video be uploaded? And are these 30 marks a part of the 50 we need to get the certificate?

Basically we get the certificate if we get 50 on the exam. It is mandatory to answer 2 questions on the forum. But is project mandatory too?

Kindly help!