user: Question: When did an away team score 7.8 (50)?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Hawthorn', '8.10 (58)', 'Melbourne', '5.10 (40)', 'Glenferrie Oval', 27500.0, '15 July 1961']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Away team score" = '7.8 (50)';