Well that's barely any different to the 52.5 - 64% range I formulated based on logical assumptions. Yes. As per my original post. The flaw in this argument is that you are assuming equal weighting on both groups. But based on historical data and the obvious incentive to clear this paper before it becomes two papers: - There are ~ 250 re-sitters who were already pass standard students and they will drive the pass rate up - There are ~ 634 students just taking a swing at this paper and they will drive the pass rate down So the numbers driving down the pass rate exceed the numbers driving it up by a factor of 2.5.