The single "21 Questions" featuring Nate Dogg is straight off of 50 Cent's album Get Rich or Die Tryin'. The song was released on April 29, 2003 and was written by 50 Cent, K. Risto, J. Cameron and V. Cameron.
Dr. Dre worked with 50 Cent on their album. It was said that Dr. Dre didn't want this song on the album because it wasn't "too gangsta" enough. 50 Cent explained to Dr. Dre saying: "I'm two people, I've always had to be two people since I was a kid, to get by. To me that's not diversity, it's necessity."
Since the release as a single, the song had hit the peak on the Billboard Hot R&B/Hip-Hop Songs at number 50 and the Billboard Hot 100 at number one.