05. SUM and COUNT quiz.txt

1. Select the statement that shows the sum of population of all countries in 'Europe'

SELECT SUM(population) FROM bbc WHERE region = 'Europe'

2. Select the statement that shows the number of countries with population smaller than 150000

SELECT COUNT(name) FROM bbc WHERE population < 150000

3. Select the list of core SQL aggregate functions

AVG(), COUNT(), MAX(), MIN(), SUM()

4. Select the result that would be obtained from the following code:

No result due to invalid use of the WHERE function

5. Select the statement that shows the average population of 'Poland', 'Germany' and 'Denmark'

SELECT AVG(population) FROM bbc WHERE name IN ('Poland', 'Germany', 'Denmark')

6. Select the statement that shows the medium population density of each region

SELECT region, SUM(population)/SUM(area) AS density FROM bbc GROUP BY region

7. Select the statement that shows the name and population density of the country with the largest population

SELECT name, population/area AS density FROM bbc WHERE population = (SELECT MAX(population) FROM bbc)

8. Pick the result that would be obtained from the following code:

Table-D
Americas	732240
Middle East	13403102
South America	17740392
South Asia	9437710