Question 3.107

77. For each of the graphs below, answer the following questions.

image
  1. Color the vertices (if possible) with three different colors.
  2. Color the vertices (if possible) with four different colors.
  3. Find the chromatic number of the graph.

77.

(a) Graph in: (a) Yes (b) No (c) Yes (d) Yes (e) No (f) No

(b) Graph in: (a) Yes (b) No (c) Yes (d) Yes (e) Yes (f) Yes

(c) Graph in: (a) 3 (b) 5 (c) 3 (d) 2 (e) 4 (f) 4