The object of this quiz is to click on the circle containing the largest population. When you begin you'll be shown 2 circles on the map with radii between 10 and 250 miles which do not intersect. Click on the one with the larger population within it (based on US census tract info) then 'Submit' - if you are correct you'll move on. One incorrect round and the quiz is over. Every 5 rounds the number of circles on the map will increase by 1. Try to build the longest streak of correct circles. Circles displayed will always be non-intersecting.
NOTE: You may have to zoom out to see all circles, occasionally a AK/HI circle will be included. Also, only population within the US is included in the total, any Canada/Mexico coverage counts as 0 population within the circle.
Quiz Takers 
Doesn’t seem like this one is working anymore? I got a score of -153 after 5 cities guessed and the quiz didn’t end.
Odd – I just tried it and it worked fine.
Leesburg, VA is less than 50k, I believe. Not trying to be rude. It’s just that the instructions say that the cities we guess will be between 50k-100k.
Yeah maybe when I made the quiz it had an estimated pop of just over 50K.
I think this one is a bit extreme. Would it make sense to do a “mid-size” cities quiz for, say, the 100k-250k range, and a “large” cities quiz for 250k+?
Agreed. Very fun quiz, but I only knew where I was if I was lucky enough to come across a sign that gave the name of the city/town.