What's the sum of the Area (KM 2) that's got a Population that's smaller than 90?
CREATE TABLE table_name_20 (
    area__km_2__ VARCHAR,
    population INTEGER
)
SELECT COUNT(area__km_2__) FROM table_name_20 WHERE population < 90
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What's the sum of the Area (KM 2) that's got a Population that's smaller than 90? ### Input: CREATE TABLE table_name_20 (
    area__km_2__ VARCHAR,
    population INTEGER
) ### Response: SELECT COUNT(area__km_2__) FROM table_name_20 WHERE population < 90