Classical antiquity and computational modelling have little in common but both feature among the hardest subjects at the University of Otago.
The subjects with the highest and lowest pass rates from 2009 to 2015 were revealed in an Official Information Act request originally provided to student magazine Critic.
The subject with the lowest pass rate in 2015 — 70% — was Greek, which involves reading major works in Greek and Roman literature.
The closely linked subject classics also featured, with the lowest pass rates at 77%.
Other papers students struggled with in 2015 included chemistry, Pacific island studies (both 75%), computer and information science (76%) and biology (77%).
Computational modelling consistently featured among the toughest subjects, with a 68% pass rate in 2010, which was matched only by finance and quantitative analysis, which had the same pass rate in 2011.
The subjects with the highest pass rates included many within the health sciences, some of which had 100% pass rates over the six-year period.
However, a university spokeswoman said not much could be read into the pass rates, particularly for subjects which had competitive entry.
"These data do not take into account the differing nature of student cohorts in the various subject areas, variations in course content, variations in the nature of course delivery, differences between professional programmes and general areas of study, and a range of other variables all affecting pass rates."
The spokeswoman criticised the interpretation in the Critic.
"To take just one example of the potential for misunderstanding, the Critic article implies that high pass rates in medicine, dentistry and other professional programmes show that these subjects are not as difficult as is sometimes thought.
"This overlooks competition for limited places in these restricted-entry programmes, resulting in very high-calibre student cohorts for whom higher pass rates might be expected," she said.