Statement 1 is correct: Mandamus is a command issued by the court to a public official asking him to perform his official duties that he has failed or refused to perform. It can also be issued against any public body, a corporation, an inferior court, a tribunal, or a government for the same purpose. It is usually not usable against a private entity unless it is entrusted with a public duty. Statement 2 is correct: As explained above, Mandamus can be used against a government corporation and/or company when it is discharging a "public duty", so the statement is incomplete. Public Duty is Key: Mandamus aims to compel performance of a public duty, not just private functions. Statement 3 is correct: Quo Warranto is issued by the court to inquire into the legality of the claim of a person to a public office. Hence, it prevents illegal usurpation of public office by a person. Unlike the other writs, this can be sought by any interested person and not necessarily by the aggrieved person. Note (on Statement 2): In UPSC Prelims, statements must be judged as written, without adding extra conditions. A company does not become subject to the writ of Mandamus only because it is a Government company. Government ownership by itself is not enough. Since Statement 2 is framed in this limited and absolute sense, and no additional condition like “public duty” is mentioned, the statement is treated as correct.