1 votes 1 votes Suppose a simple graph has $45$ edges, $5$ vertices of degree $6$, and all others of degree $5$. How many vertices does the graph have? Graph Theory go2025-dm-4 numerical-answers graph-connectivity degree-of-graph + – gatecse asked Sep 14, 2020 • recategorized Sep 14, 2020 by Lakshman Bhaiya gatecse 128 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 3 votes 3 votes Let the total number of vertices be $n$. Using sum of the degrees theorem:$5\times 6 + (n-5)\times 5 = 2e = 90$ $\implies 30+5(n-5)=90$ $\implies n = 17$ So, the correct answer is $17$. gatecse answered Sep 14, 2020 • selected Sep 11, 2021 by Arjun gatecse comment Share Follow See all 0 reply Please log in or register to add a comment.