CREATE TABLE table_21842 ("Club" TEXT, "Played" TEXT, "Won" TEXT, "Drawn" TEXT, "Lost" TEXT, "Points for" TEXT, "Points against" TEXT, "Tries for" TEXT, "Tries against" TEXT, "Try bonus" TEXT, "Losing bonus" TEXT, "Points" TEXT)

Name the won when tries against is 72
SELECT "Won" FROM table_21842 WHERE "Tries against" = '72'
SELECT "Won" FROM "table_21842" WHERE "Tries against" = '72'