The largest city in Brazil, Sao Paulo, has a population of about 11 million. Based on the rank-size rule, what is the population of the second-largest city, Rio de Janeiro, most likely to be?

5-6 million

Explanation:

Based on the ranking of the nations the largest city in the brazil's as Sao Paulo that has a population of about 11 million and the next city in line with this is the Rio de Janeiro which has a population of about 5 to 6 million. The rank-size rule is a rule that states that the population of the city will have the highest ranks and then the ranks of the city will tend to drops as per the decrease of the population and the amenities.

5-6 million