Which Buddhist text provides an account of the 16 Mahajanapadas of the 6th century B.C.?

Which Buddha text has described 16 Mahajanpads of 6th century B.C.?

Which was the first capital of ancient Mahajanapada Magadh?

Champa was the capital of which Mahajanapada?

Which one among the following mahajanapadas in ancient India was an oligarchy?

During the period of 16 Mahajanapadas, Mathura was the capital of –