Upon clicking START you will be shown 5 circles, one at a time, with increasing radii: 50, 100, 250, 500 and 1000 km. The object is to move the circle to the location such that it covers the most amount of people, based on Europe population density data. You are scored based on how many people you cover compared to the maximum possible (score is based on the ratio of people in your circle compared to max possible - score is not an exact ratio but falls faster than that).
PLEASE NOTE: ALL of Turkey is included in counting population (not just European portion), and the portion of Russia west of 61.5 degrees E (just east of Chelyabinsk). Nothing outside Europe (such as Africa or middle east other than Turkey) is included toward the population count within a circle.
Quiz Takers 
btw can you also create largest cities per French region quiz? I just want to name cities in Ile-de-France but it’s split into several departments so there’s no convenient way to do it
I think the “Top Cities:” feature is broken on this quiz. I only named 6 cities, and it says I’ve listed the top 1,480 cities. This happens in every department. I am running the latest version of Firefox.
this has been fixed.
tried Seine Saint Denis now and in the 50 hardest table there was
Saint Denis – villetaneuse%
Montreuil – dugny%
and in the missed table all of the other cities (including the previous 2 with the correct city before the %)
it’s because you were the first playing that department.
might be an issue because I’m the first one to take the quiz but for some reason all cities were showing up in the missed list (including the ones I got)