Given the CITY and COUNTRY tables, query the sum of the populations of all cities where the CONTINENT is 'Asia'.

To answer this question, you would need to join the CITY and COUNTRY tables on the appropriate column (likely COUNTRY_ID or similar), then filter for rows where the CONTINENT is 'Asia', and finally sum the POPULATION column. Here is an example of how you might write this query in SQL:

SELECT SUM(CITY.POPULATION) 
FROM CITY 
JOIN COUNTRY ON CITY.COUNTRY_ID = COUNTRY.COUNTRY_ID 
WHERE COUNTRY.CONTINENT = 'Asia';

Please replace COUNTRY_ID with the actual column that links the CITY and COUNTRY tables in your database.

This query works by first joining the CITY and COUNTRY tables together based on their common column (COUNTRY_ID). This creates a new table that includes columns from both CITY and COUNTRY. The WHERE clause then filters this table to include only rows where the CONTINENT is 'Asia'. Finally, the SUM function adds up the POPULATION of all these rows.