How many different parties are there?
select count(distinct party) from driver
How many drivers are from Hartford?
select count(*) from driver where home_city = 'Hartford'
Among these drivers, how many of them are older than 40?
select count(*) from driver where home_city = 'Hartford' and age > 40
Show their parites.
select party from driver where home_city = 'Hartford' and age > 40