3 3 votes Let $G=(V,E)$ where $V=\left \{ 1,2,3,4,.....,150\right \}$ and $(u,v) \in E$ if either $(u mod v) =0$ or $(v mod u)=0$.The Chromatic number of G is ? Graph Theory zeal-test-series graph-theory discrete-mathematics graph-coloring numerical-answers + – Kabir5454 943 views answer comment Share Follow Print See all 3 Comments 3 3 Comments reply Aaru_2023 commented Jan 3, 2023 reply Follow flag @Kabir5454 is it 8? 0 0 replyShare Kabir5454 commented Jan 3, 2023 reply Follow flag yes 0 0 replyShare Shoto commented Jan 4, 2023 reply Follow flag I am not sure if it is correct or not but this is how I tried to solved it, To maximise the chromatic number we have to find the maximum size of complete graph where every vertex is connected to each other. Now first take vertex $1$, then take $2$ Now next vertex to which both $1$ and $2$ are connected is $4$ Next vertex to which $1$, $2$ and $4$ are connected is $8$ Similarly we get complete graph with vertices $\{1,2,4,8,16,32,64,128\}$ and this will be the largest complete graph. And we need $8$ colours to color them. 1 1 replyShare Please log in or register to add a comment.