GATE CS Graphs questions

Consider the weighted undirected graph with $4$ vertices, where the weight of edge $\{i,j\}$ is given by the entry $W_{ij}$ in the matrix $W$. W=$\begin{bmatrix} 0&2 &8 &5 \\ 2&0 &5 &8 \\ 8&5 &0 &x \\ 5& 8 &x &0 \end{bmatrix}$ The largest possible integer value of $x$, for which at least one …

Which one of the following hash functions on integers will distribute keys most uniformly over $10$ buckets numbered $0$ to $9$ for $i$ ranging from $0$ to $2020$?

Let $G=(V,E)$ be a directed graph where $V$ is the set of vertices and $E$ the set of edges. Then which one of the following graphs has the same strongly connected components as $G$ ?

Let $G$ be the graph with $100$ vertices numbered $1$ to $100$. Two vertices $i$ and $j$ are adjacent if $\vert i-j \vert =8$ or $\vert i-j \vert=12$. The number of connected components in $G$ is