If it's 20km round trip that's not too bad. 20km each way is a bit much.

I read it as 20km each way, 40km total. I agree that a 10km each way trip is far more reasonable. In fact that's only slightly longer than my 5 mile bike commute, and I bet they have fewer 90F (32c) and 80% humidity days than we do here.

I read it that way, but then, that would mean there is no school within 20 km, so an empty space where schools around are separated by 40 km. I think there are very few possible spaces like that in Netherlands, or in most Western Europe. Or then we are talking about high-schools, which are more sparse.

So I guess 2x10 km is the most likely answer. And that's already a lot.

I ment 10km each way, 20km each way would feel excessive to me as well. For those cases (in dutch rural areas) there would almost always be some kind of bus service to take kids.