6.042 at MIT is often taught using recitations. Suppose it happened that 8 recitations were needed, with
two or three staff members running each recitation. The assignment of staff to recitation sections, using
their secret code names, is as follows:
\item R1: Maverick, Goose, Iceman
R2: Maverick, Stinger, Viper
R3: Goose, Merlin
R4: Slider, Stinger, Cougar
R5: Slider, Jester, Viper
R6: Jester, Merlin
R7: Jester, Stinger
R8: Goose, Merlin, Viper
Two recitations can not be held in the same 90-minute time slot if some staff member is assigned to
both recitations. The problem is to determine the minimum number of time slots required to complete
all the recitations.
a) Recast (translate) this problem as a question about coloring the vertices of a particular graph.
b) Draw the graph and explain what the vertices, edges, and colors represent. (One free flow-chart
building application that will work to make such an image is https://draw.io
c) Show a coloring of this graph using the fewest possible colors; prove why no fewer colors will
work.
d) What is the resulting schedule of recitations implied by the coloring?