This question is from " Networks, Crowds, and Markets: Reasoning about a Highly Connected World" textbook in chapter 5

Suppose that a team of anthropologists is studying a set of three small villages that neighbor one another. Each village has 30 people, consisting of 2-3 extended families. 5.6. Everyone in each village knows all the people in their own village, as well as the people in the other villages. When the anthropologists build the social network on the people in all three villages taken together, they ?nd that each person is friends with all the other people in their own village, and enemies with everyone in the two other villages. This gives them a network on 90 people (i.e., 30 in each village), with positive and negative signs on its edges. According to the de?nitions in this chapter, is this network on 90 people balanced? Give a brief explanation for your answer.