Passage: Like the New York City Subway and in contrast with the London Underground the Paris Métro mostly uses two-way tunnels. As in most French métro and tramway systems, trains drive on the right (SNCF trains run on the left track). The tracks are standard gauge (1.435 metres). Electric power is supplied by a third rail which carries 750 volts DC.

Question: How many volts are provided by the third rail?
750