I just had a look through some of the questions of the test and it seems very fair to me. Simple scientific sorts of questions that have good clear questions with answers that can be very definitely said.

I would chock it up to finland being a more homogenous society. Many of those small european countries have top notch education systems, but they are small and everybody is well off. I personally think that the US needs to find its best way to educate, not somebody else's.

They also have free college. I'm jealous.