CREATE TABLE table_64530 ("Team" TEXT, "Outgoing manager" TEXT, "Manner of departure" TEXT, "Date of vacancy" TEXT, "Replaced by" TEXT, "Date of appointment" TEXT, "Position in table" TEXT)

what is the date of vacancy when the team is firpo and replaced by is oscar benitez?
SELECT "Date of vacancy" FROM table_64530 WHERE "Team" = 'firpo' AND "Replaced by" = 'oscar benitez'
SELECT "Date of vacancy" FROM "table_64530" WHERE "Replaced by" = 'oscar benitez' AND "Team" = 'firpo'