Consider the following graph. What is the weight of minimum spanning tree?

2021

Consider the following graph.

What is the weight of minimum spanning tree?

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  1. A.

    50

  2. B.

    60

  3. C.

    70

  4. D.

    80

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Show answer & explanation

Correct answer: B

To find the weight of the minimum spanning tree (MST), apply Kruskal's algorithm:

Step 1: List all edges and their weights: Q-R (5), S-T (10), Q-T (15), Q-S (20), P-Q (30), P-S (40).

Step 2: Sort the edges in ascending order of weight: 5, 10, 15, 20, 30, 40.

Step 3: Select edges in order, avoiding cycles:

  • Add edge Q-R (weight 5).

  • Add edge S-T (weight 10).

  • Add edge Q-T (weight 15).

  • we cannnot Add edge Q-S (weight 20). as it forms a cycle .

  • add edge P-Q (weight 30)

Step 4: The selected edges form a spanning tree with no cycles. The total weight is 5 + 10 + 15 + 30 = 60.

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