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World 10 Circle Population Challenge

Directions

The object of this quiz is to place 10 circles of radius 1000 km on the map so that they contain the largest total population.

When you begin you’ll be given a 1000-km radius circle centered on the map. Move it using the mouse and click SUBMIT. You will be given a score for that circle corresponding to the total population contained within it based on world population density at https://human-settlement.emergency.copernicus.eu/index.php. Try to complete all 10 circles with the highest total score.

Any INTERSECTING areas are only counted one time, so no population will be counted more than once.

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You will be shown 10 different circles of radius 250-2000 km. Using the slider (or manually typing into the box below the slider), guess the population contained within each circle then click SUBMIT for each one. Populations are based on world population density at https://human-settlement.emergency.copernicus.eu/index.php.

World 20 Circle Population Challenge

The object of this quiz is to place 20 circles of radius 1000 km on the map so that they contain the largest total population.

When you begin you'll be given a 1000-km radius circle centered on the map. Move it using the mouse and click SUBMIT. You will be given a score for that circle corresponding to the total population contained within it based on world population density at https://human-settlement.emergency.copernicus.eu/index.php. Try to complete all 20 circles with the highest total score.

Any INTERSECTING areas are only counted one time, so no population will be counted more than once.

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World City Grid Blackout Largest City Challenge

Type 'easy' or 'hard' to begin the quiz. Easy is a 15-degree grid, hard is a 10-degree grid. Then, try to name the LARGEST city in each grid square which fits the category label for each square. To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period). You are given a score from 0 to 100 based on your answer's population compared to the largest city accepted in that square (100 being you named the largest city).

LETTER: means the city starts with that letter.
NUMBER RANGE: (such as 2-5, 10+) means the city contains that many letters (excluding spaces and special characters).
POPULATION RANGE: (such as 50-100K) means the city has that range for its population.
2+ WORDS means the city name has 2 or more words (words denoted by a space or hyphen).

At the end of the quiz the largest population missed answer will show in each unanswered square, and for those answered the largest city will be listed if you didn't answer it.

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blakeaz

15 days ago

Im stuck around 4.6 billion, I wonder if anything in the Americas or in Africa is worth it

tendog

15 days ago

Reply to blakeaz

there are 2 entirely separate circles in africa that get ~375.0M and ~320.8M

slowpoke

15 days ago

how do I save my score?

BenNemo

15 days ago

Reply to slowpoke

It saves automatically when you’ve placed all ten circles. You have to refresh the page to see it.

theion666

21 days ago

I can’t see the circles. When I click submit, the circle shows up but I am unable to see or interact with it before that

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darin

20 days ago

Reply to theion666

You have to click ‘Next Location’ after Submit to have the next circle pop up on the map. It will always show at the same initial spot on the map (northern Africa).