Q6 (6 pts). Find all the countries with negative gdp that are NOT from the following regions: 'North America', 'Asia', 'Europe', Oceania, 'Arctic Region'. Sort the results by gdp in ascending order. DO NOT USE more than one AND keywords in your query.

Q7 (6 pts). Calculate the total population of each region. Your output should include two columns: region and total_pop. Sort the results by total_pop in descending order.

Q8 (10 pts). Find the highest and lowest gdp of each region. Your output should have three columns: region, min_gdp, max_gdp, Sort the results by region in alphabetical order.

Q9 (10 pts). List regions with more than 15 countries. Your output should not contain duplicate rows. Show these regions and their corresponding number of countries. Sort the results by the number of countries in ascending order.

Q10 (10 pts). Calculate the population density of each country and list the top-10 countries and their respective population densities. Your output should have two columns: country and pop_density. Sort the results by pop_density in descending order. The population density of a country is calculated as the population divided by the area of the country. You should exclude any country with missing area or missing population information from your calculation.