Explanation:

40 per cent

Chota Nagpur, plateau in eastern India, in northwestern Chhattisgarh and central Jharkhand states. The plateau is composed of Precambrian rocks (i.e., rocks more than about 540 million years old). Chota Nagpur is the collective name for the Ranchi, Hazaribagh, and Kodarma plateaus, which collectively have an area of 25,293 square miles (65,509 square km). Its largest division is the Ranchi Plateau, which has an average elevation of about 2,300 feet (700 metres). The Chota Nagpur area has the most valuable concentration of mineral resources in India.