I Want 20 randoms questions out of 60. Is it possible?

Hi there!

I have a quizz with 60 questions BUT I only want people to get 20 questions. I would like a set of 20 questions taken at randon from the 60 I have entered. Each questions is 1 points and 16/20 is needed to pass the test.  I have looked to see if it's possible but I cannot anything. Can someone help me please?