Let there is an undirected graph with 10 nodes with the following edges (x-y means x and y are connected):

1-2, 1-5, 1-7, 2-3, 2-5, 3-4, 3-5, 4-5, 4-10, 5-6, 6-7, 6-8, 6-9, 6-10, 7-8, 8-9, 9-10.

Now, I. Express these relations as a graph. II. Apply BFS considering 1 as the source node (level-0 node). Draw the BFS tree and mark each level. If there are multiple options at any step, pick the node with smaller index.

Now, apply DFS considering 1 as the source node. If there are multiple options at any step, pick the node with smaller index. Draw the DFS tree. Also, mention all the back-edges.