user: Question: What is the Attendance number when the Opponent was Purdue?
Columns: ['Date', 'Opponent#', 'Site', 'Result', 'Attendance']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['10/06/1928', 'Creighton', 'Memorial Stadium • Minneapolis, MN', 'W40-0', '20,000']
SQL:

assistant: SELECT "Attendance" FROM "Table" WHERE "Opponent#" = 'Purdue';