बिहार में प्रति हजार वर्ग किमी रेलमार्ग सघनता कितनी है ? - What is the railway density per thousand sq km in Bihar? - Bihar Me Prati Hazar Warg KM Relamarg Saghanta Kitni Hai ? Bihar Gk in hindi, Government Schemes 36.15 KM question answers in hindi pdf 32.15 KM questions in hindi, Know About 40.15 KM Bihar Gk online test Bihar Gk notes in hindi quiz book 30.15 KM