A City Consists of Three Boroughs, and Each Borough Has

A city consists of three boroughs, and each borough has five neighborhoods and each neighborhood consists of ten houses. You have been hired to run a fiber-optic cable, networking all of the houses to each other. No matter the length, it costs $100 to connect any one house to any other house. Based on all of this information, what will it cost to network all of the houses in the city together so that there are
no redundancies? Hint: Think of each house as a vertex.