Before Champaran Satyagraha, the farmers of Champaran used to follow the 'Panchkathiya' system, whereby five katthas of land in a bigha had to be planted with ___.
The angles of depression of two ships from the top of a light house are 60° and 45° towards east. If the ships are 300 m apart, the height of the light house is
Based on the common features like presence of notochord and dorsal hollow neural system, animals like fishes, amphibians, reptiles, birds along with mammals are included in which Phylum?