user: Question: HOW MANY TIMES WAS Ludacris THE INTERVIEW SUBJECT FOR THE 20 QUESTIONS COLUMN?
Columns: ['Date', 'Cover model', 'Centerfold model', 'Interview subject', '20 Questions', 'Pictorials']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1-06', 'Lisa Guerrero', 'Athena Lundberg', 'Mark Cuban', 'Kate Beckinsale', 'Lisa Guerrero']
SQL:

assistant: SELECT COUNT("20 Questions") FROM "Table" WHERE "Interview subject" = 'Ludacris';