Give the step-by-step reasoning process and then the final answer. A farmer has 51 cows. The farmer adds five new cows to its herd and then sells a quarter of the herd. How many cows does the farmer have left?
The farmer has 51 + 5 = 56 cows in its herd. The farmer sells 56 / 4 = 14 cows of the herd. The farmer now has 56 - 14 = 42 cows.
The final answer: 42.