Question: Who was the away team when Manchester United played at home on 10 February 1951?
SQL: SELECT "Away team" FROM "2-17520911-6" WHERE "Date" = '10 February 1951' AND "Home team" = 'Manchester United';

Question: Which tie did Huddersfield Town play as an away team?
SQL: SELECT "Tie no" FROM "2-17520911-6" WHERE "Away team" = 'Huddersfield Town';