Bihar is a state in eastern India. Bihar is the 12th largest state in terms of geographical size at 38,202 sq mi (99,200 km²), and 3rd largest by population. Close to 85 percent of the population lives in villages. Almost 58 per cent of Biharis are below the age of 25,which is the highest proportion in India. Bihar lies mid-way between the humid West Bengal in the east and the sub humid Uttar Pradesh in the west which provides it with a transitional position in respect of climate, economy and culture. It is bounded by the country of Nepal to the north and by Jharkhand to the south. The Bihar plain is divided into two parts by the river Ganga which flows through the middle from west to east. Bihar has notified forest area of 6,764.14 km², which is 7.1 per cent of its geographical area. Hindi and Urdu are the official languages of the state, whilst the majority of the people speak one of the Bihari languages Bihar is known to be the richest mineral output (40%) in the country. The state is the world's chief supplier of mica and the country's largest producer of coal.