CREATE TABLE table_204_155 (id DECIMAL, "rank" DECIMAL, "heat" DECIMAL, "athlete" TEXT, "nationality" TEXT, "time" DECIMAL, "notes" TEXT)

what is the difference between mexico and brazil time
SELECT ABS((SELECT "time" FROM table_204_155 WHERE "nationality" = 'mexico') - (SELECT "time" FROM table_204_155 WHERE "nationality" = 'brazil'))
SELECT ABS((SELECT "time" FROM "table_204_155" WHERE "nationality" = 'mexico') - (SELECT "time" FROM "table_204_155" WHERE "nationality" = 'brazil'))