Forgive my ignorance, but at what age do students typically take this test?
Brian Luff

In that case it’s very similar to a situation that got a lot of coverage here in the UK at the end of the last academic year. If this link works, you’ll see that a relatively simple probability question in a GCSE paper sparked outrage and demands for grading boundaries to be adjusted. GCSEs are taken at 15–16, and it’s two more years before youngsters may then progress to university. I’m not joking, or bragging, but I found I could prove the validity of the given quadratic equation in my head. Provided you’re aware that the probability of two independent events is the product of their individual probabilities the rest is trivial. I guess if you were asleep when they were teaching that then the question is a lot more difficult. Most astonishing were some of the comments… at the link, you may see one where a student claims that her mother (and a bunch of other maths graduates at her accountancy firm) took two hours to do it. I’m just glad my company doesn’t use such a useless accountancy firm.