Answer :
The question is asking to state the reason why the cow keep jumping over the barrel, base on my research and further understanding, the possible answer would be that She was practicing for a moonshot. I hope you are satisfied with my answer and feel free to ask for more
It is a joke used in mathematics. The answer could be something logical. In this case it is moonshot. There are similar examples which have witty answers. These answers show that it is correct, but at the same time it is funny.