CREATE TABLE table_21887 ("Tie no" FLOAT, "Home team" CLOB, "Score 1" CLOB, "Away team" CLOB, "Attendance" FLOAT)

In what tie were Leeds United the away team?
SELECT MAX("Tie no") FROM table_21887 WHERE "Away team" = 'Leeds United'
SELECT MAX("Tie no") FROM "table_21887" WHERE "Away team" = 'Leeds United'