The chromatic number of a graph is the minimum number of colours used in a proper colouring of the graph. The chromatic number of the following graph is ________

The chromatic number of a graph is the minimum number of colours used in a proper colouring of the graph. Let $G$ be any graph with $n$ vertices and chromatic number $k$. Which of the following statements is/are always TRUE?

The number of edges present in the forest generated by the DFS traversal of an undirected graph G with 100 vertices is 40. The number of connected components in G is ________

Let G be a simple, finite, undirected graph with vertex set {$$v_1,...,v_n$$}. Let $$\Delta(G)$$ denote the maximum degree of G and let N = {1, 2, ...} denote the set of all possible colors. Color the vertices of G using the following greedy strategy:

for $$i=1,....,n$$

color($$v_i)$$ $$\leftarrow$$ min{$$j\in N$$ : no neighbour of $$v_i$$ is colored $$j$$}

Which of the following statements is/are TRUE?