Table: fa_cup_matches_42
Columns: tie_no
home_team
score
away_team
date

Question: Who was the away team when Manchester United played at home on 10 February 1951?
SQL: SELECT "away_team" FROM fa_cup_matches_42 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 fa_cup_matches_42 WHERE "away_team" = 'huddersfield town'