Yeh as I said above do the 3 mqarks questions first then the 2 markers , then if you do run out of time you havent got 3 mark questions outstanding , made sense to me at the time. DONT RELY ON BRISTOL the questions are similar but numerical values change. That said if you can work out the answers on the questions that will stand you in good stead for the exam but dont learn answers to numerical questions .
On my first gnav paper there were 9 crp/5 questions and 6 chart related questions , the following month on the retake there were two of each so there really is no way of saying . On first paper there were no PSR/PET questions on the second there were 4 ,these are a give away and worth 3 and two marks so get them get of the way if they appear .
Just keep your eye on the time as that is your biggest enemy on gnav many many people end the eam with outstanding questions .
Good Luck