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?

Let $$U = \{ 1,2,3\} $$. Let 2$$^U$$ denote the powerset of U. Consider an undirected graph G whose vertex set is 2$$^U$$. For any $$A,B \in {2^U},(A,B)$$ is an edge in G if and only if (i) $$A \ne B$$, and (ii) either $$A \supseteq B$$ or $$B \supseteq A$$. For any vertex A in G, the set of all possible orderings in which the vertices of G can be visited in a Breadth First Search (BFS) starting from A is denoted by B(A).

If $$\phi$$ denotes the empty set, then the cardinality of B($$\phi$$) is ___________