- Greatest popoulation difference: I would guess that Thimphu and Kathmandu are smaller than Beijing and New Delhi?
- Maybe you should accept Lima, too, for greatest elevation difference? I know it touches the ocean but don't know if it's considered at 0 altitude
- Kinshasa and Brazzaville: I suppose you could put the second closest together cities (and the second farthest apart pair); or maybe closest together by country size (distance between them divided by sum of country ares?)
- Capitals at the different sides of the equator/prime meridian (but maybe they're too many?)
- Difference in average temperature
Also, you could do a similar 'triborder' quiz where you consider capital of 3 countries bordering each other.
Do you have a list of country borders in a good excel format or something? If so I'd be happy to use it for my quizzes! :P
re: your suggestions for other categories... 2nd closest could be good I might add that. 2nd farthest apart I'm pretty sure would just be Moscow and Beijing so that wouldn't really add anything while at the same time unnecessarily dropping a hint for the farthest answer.
Closest by country size? That sounds like it would take a *lot* of work to figure out, and I would have no idea who would win in that equation either. I don't think most people would even bother guessing, that's just too confusing.
The equator/meridian thing is a good idea but, yes, there are quite a few that would fit that description. That might be better as a subject for a different quiz.
Difference in average temperature is a very good idea. I may look into adding that one as well as 2nd closest capitals.
I do not have any such Excel format... but I've got most of the world in my head and when that fails there's googlemaps, Wikipedia, etc. to help out.
Here's a couple of things I thought after reading your messages:
- to add more answers you could perhaps have farthest/closest capitals for each continent
- closest by country size: actually I meant something else but I certainly didn't choose the right wording. I meant that you take the distance between the capital cities and divide it by the sum of the areas of the two countries (perhaps you should actually square root it since you're comparing an area to a distance) and see what the maximum/minimum values are. I guess this would be won by Kinshasa/Brazzaville
However, since authoring this quiz QM has updated the quiz editor with a feature that suggests type-ins. Given that capital cities are common answers on quizzes here, I assume those are all among the suggestions. I'll check it out and see if I can add the suggested type-ins so it's consistent with the rest of the site.