Question: How many former members from the band where Zack De La Rocha was a rapper/vocalist took part in the Audioslave discography? 
Sentence (from "Rage Against the Machine discography"): The discography of Rage Against the Machine, an American rap metal band, consists of four studio albums, two live albums, one compilation album, one demo album, 17 singles, four video albums and 15 music videos. Formed in Los Angeles, California in 1991 by vocalist Zack de la Rocha, guitarist Tom Morello, bassist Tim Commerford and drummer Brad Wilk, the band signed to Epic Records and released its self-titled debut album in 1992.
Relevant evidence: No