Table: greek_regions
Columns: no
region
capital
area_km
area_sq_mi
population
gdp_bn

Question: what is the gdp ( bn ) where capital is capital?
SQL: SELECT "gdp_bn" FROM greek_regions WHERE "capital" = 'Capital'

Question: what is the population where the area (sq. mi.) is area (sq. mi.)?
SQL: SELECT "population" FROM greek_regions WHERE "area_sq_mi" = 'Area (sq. mi.)'