James, Carl, Mark, Antonio, Phillip, and Brad Are Friends at College

Essay

James, Carl, Mark, Antonio, Phillip, and Brad are friends at college. Carl, Antonio and
Phillip have calculus together. Brad, Carl, and Mark have the same English composition
class. Draw a graph with vertices representing students and edges representing the relation
"take a common class". How many components does the graph have? Identify a subgraph
that is a complete subgraph with three vertices.