Passage: The Chamber of Deputies has 630 elected members, while the Senate has 315 elected members. The number of deputies and senators was fixed by a constitutional amendment in 1963: in its original text, the Constitution provided for a variable number of Members of Parliament depending on the population. The Senate of the Republic also includes, in addition to the elected senators, a small number of unelected members (senators for life). There are two categories of senators for life. Former Presidents of the Republic are senators for life by law, unless they renounce this privilege. Furthermore, the President of the Republic can appoint up to five Italian citizens as senators for life "for outstanding merits in the social, scientific, artistic or literary field".Different voting ages are mandated for each house: any Italian citizen who is 18 or older can vote in the election of the Chamber of Deputies, while the voting age for the Senate of the Republic is 25. Similarly, the two houses have a different age of candidacy: deputies are required to be 25 or older, while elected senators must be 40 or older. No explicit age limit is required to be appointed senator for life (but Presidents of the Republic must be 50 or older).

Question: How many members of the Senate are elected?
315