Answer
Pittsburgh has 6 games during the week.
Pittsburgh plays the following teams:
St. Louis, Chicago, Philadelphia, Montreal
Pittsburgh plays St. Louis once.
Pittsburgh plays Chicago once.
Pittsburgh plays Philadelphia twice.
Pittsburgh plays Montreal twice.
Work Step by Step
The vertex for Pittsburgh has 6 edges connected to it, so Pittsburgh has 6 games during the week.
If an edge connects the vertex for Pittsburgh to the vertex for another team, then Pittsburgh plays that team. Pittsburgh plays the following teams:
St. Louis, Chicago, Philadelphia, Montreal
The number of edges connecting the vertex for Pittsburgh to the vertex for another team shows how many times Pittsburgh plays that team.
Pittsburgh plays St. Louis once.
Pittsburgh plays Chicago once.
Pittsburgh plays Philadelphia twice.
Pittsburgh plays Montreal twice.
