CREATE TABLE table_17939 ("Year" TEXT, "Championship" TEXT, "54 holes" TEXT, "Winning score" TEXT, "Margin" TEXT, "Runner ( s ) -up" TEXT)

What was the winning score of the PGA Championship (3)?
SELECT "Winning score" FROM table_17939 WHERE "Championship" = 'PGA Championship (3)'
SELECT "Winning score" FROM "table_17939" WHERE "Championship" = 'PGA Championship (3)'