user: Question: What is the location attendance of the game with A. Horford (10) as the highest rebounds and J. Johnson (21) as the highest points?
Columns: ['Game', 'Date', 'Team', 'Score', 'High points', 'High rebounds', 'High assists', 'Location Attendance', 'Series']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'April 20', '@ Boston', '81–104', 'A. Horford (20)', 'A. Horford (10)', 'J. Johnson (7)', 'TD Banknorth Garden 18,624', '0–1']
SQL:

assistant: SELECT "Location Attendance" FROM "Table" WHERE "High rebounds" = 'A. Horford (10)' AND "High points" = 'J. Johnson (21)';