answers: ten
context: Varanasi Metro The Varanasi Metro was a rapid transit proposed for the city of Varanasi, Uttar Pradesh, India. The proposed system consisted of 2 corridors span from BHEL (Tarna, Shivpur) to Banaras Hindu University (19.35 km) and Benia Bagh to Sarnath (9.885 km). The feasibility study of the project was done by RITES and was completed in June 2015. However, the good ridership in Varanasi is doubtful like other towns in Uttar Pradesh. The most feasible cities of having metro rails are Lucknow and Noida because these cities have the strong number of daily commuters which includes the public from </s> Surat Metro The Surat Metro is a rapid transit rail system proposed for the city of Surat in the Indian state of Gujarat. In August 2012, the Surat Municipal Corporation (SMC) proposed four rail routes for the metro project. The Government of Gujarat approved two corridors in January 2017. The corridors are; from Sarthana, Varachha to Dream City () and from Bhesan Depot to Saroli (). The project will cost 12,800 crore. Sarthana-Dream City corridor will have 21 stations and Bhesan Depot-Saroli corridor will have 16 stations. Out of approved corridor, will be elevated whereas will be underground. The project </s> Urban rail transit in India Urban rail transit in India consists of suburban rail, rapid transit, monorail, light rail, and tram systems. There are currently 10 operational rapid transit (also called 'metro') systems in ten cities in India. As of September 2018, India has of operational metro lines and 381 stations. A further 500+ km of lines are under construction. Metro rail lines in India are composed of mainly standard gauge. Projects like the Kolkata Metro and Delhi Metro used broad gauge for their earliest lines but all new projects in India are on standard gauge as rolling stock imported
question: how many cities in india have metro railway