When Brazzaville didn't work, I didn't think to try Kinshasa since they are right across the Congo from one another, so I figured they were North of the equator. Didn't dawn on me that Brazzaville was so small.
Hahaha! I felt the same way! I think I've taken every equator quiz about 5-10 times just so that I can learn through repetition. Now I think I have finally gained a vague idea of where it is.
Your figures are SO WRONG when it comes to Brazilian cities. Salvador does not have fewer inhabitants than Recife and Porto Alegre. And I know what I'm talking about, I'm from Salvador.
The numbers are by metro area. Salvador could be bigger than Porto Alegre by the city proper metric, but Porto Alegre has a lot of larger cities around it, so it adds up and surpass Salvador.
Interesting quiz - thank you. I knew the two I was missing must have been in Brazil, but Recife and Porto Alegre both escaped my mind! Off to look at a map of Brazil now...
https://pt.wikipedia.org/wiki/Lista_de_municípios_do_Brasil_por_população