From the passage provided, extract the number of episodes that made up the seventh series of Waterloo Road.

Context: The seventh series of the British television drama series Waterloo Road began broadcasting on 4 May 2011, and ended on 25 April 2012 on BBC One. The series follows the lives of the faculty and pupils of the eponymous school, a failing inner-city comprehensive school. It consists of thirty episodes, shown in three blocks of ten episodes each. The seventh series achieved an average of 5.30 million viewers in the ratings. It is the last series to be set in Rochdale, England.

Answer: The seventh series of Waterloo Road had thirty episodes.