Table: dancing_scores
Columns: rank_by_average
competition_finish
couple
total
number_of_dances
average

Question: What couple averaged 21.0?
SQL: SELECT "couple" FROM dancing_scores WHERE "average" = '21.0'

Question: What was the number of dances for the competition finish of 3?
SQL: SELECT MAX("number_of_dances") FROM dancing_scores WHERE "competition_finish" = 3