What is the average total points of gymnasts?
select avg(total_points) from gymnast
How many gymnasts are there that have total points more than 50?
select count(*) from gymnast as t1 join people as t2 on t1.gymnast_id = t2.people_id where t1.total_points > 50
How about the number of gymnasts with total points more than 57.5?
select count(*) from gymnast as t1 join people as t2 on t1.gymnast_id = t2.people_id where t1.total_points > 57.5
What are the distinct hometowns of these gymnasts?
select distinct t2.hometown from gymnast as t1 join people as t2 on t1.gymnast_id = t2.people_id where t1.total_points > 57.5