Gankhu gives it back and The Black Bull

Gankhu sees that his father is unhappy. The landlord is being unfair to the farmers and paying them less. How will Gankhu teach the greedy landlord a good lesson? Badka Devi was a generous old woman. When she was gifted a little black calf, she took care of it as if it were her child. The calf grew up to be a mighty bull and wanted to help Badka Devi live comfortably. How did the bull earn money and help her?