CREATE TABLE table_6881 ("Date" TEXT, "Score" TEXT, "Set 1" TEXT, "Set 2" TEXT, "Set 3" TEXT, "Set 4" TEXT, "Set 5" TEXT, "Total" TEXT)

What is Set 1, when Set 4 is NA, when Score is 3-0, and when Set 2 is 29-27?
SELECT "Set 1" FROM table_6881 WHERE "Set 4" = 'na' AND "Score" = '3-0' AND "Set 2" = '29-27'
SELECT "Set 1" FROM "table_6881" WHERE "Score" = '3-0' AND "Set 2" = '29-27' AND "Set 4" = 'na'