user: Question: When 318676 is the population of 2010 and 1st Class is the income classification what is the area in kilometers squared?
Columns: ['City/Municipality', 'Population (2010)', 'Area (km²)', 'Pop. density (per km²)', 'Income Classification']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Baguio City', 318676.0, '57.5', 'Category:Pages with bad rounding precision', '1st Class']
SQL:

assistant: SELECT "Area (km²)" FROM "Table" WHERE "Income Classification" = '1st Class' AND "Population (2010)" = 318676.0;