Presumably you're looking for problems with a written output to facilitate comparison with humans, like in a Turing test. How about the problem of getting a goo

Presumably you're looking for problems with a written output to facilitate comparison with humans, like in a Turing test. How about the problem of getting a good mark in an English Language GCSE exam: an exam taken by nearly all 16-year-olds in the UK. This is, of course, a non-trivial problem for many intelligent humans, including some who go on to get good degrees in unrelated subjects. Because so many of these papers are getting marked every year someone might be able to get permission to mix in a few machine-generated responses, as an experiment. Or perhaps not, because it would perhaps be a bit embarrassing if the examiners gave good marks to GPT-generated crap.