Answer: 12
Notes: 12 districts of Bihar are located on the banks of River Ganges. These 12 districts are : Buxar, Bhojpur, Saran, Patna, Vaishali, Samastipur, Begusarai, Munger, Khagaria, Katihar, Bhagalpur and Lakhisarai. The length of Ganges river in Bihar is 445 Km and the total length of Ganges river is 2525 Km. In Bihar, the length of Ganga river is maximum in Patna district.
