BIT152 Discrete Structure

Discrete Structure TU Board 2078 question paper

12 questionsSit this paper (timed)

Tribhuvan University

Bachelor of Information Technology

Semester 2 · TU Board 2078

Course Title: Discrete Structure (BIT152)

Full Marks: 60Pass Marks: 24Time: 3 hours

Candidates are required to give their answers in their own words as far as practicable.

Group A

Attempt any Two questions.(2 × 10 = 20)

  1. 1.

    Explain direct proof, indirect proof, and proof by contradiction. Use direct proof to show that "If n is an odd integer, then n³ is an odd integer". Also use indirect proof to show that "If n is an integer and n³ then n is odd".

    10
  2. 2.

    What is linear nonhomogeneous recurrence relation of degree k with constant coefficients? Find all the solutions of the recurrence relation aₙ₊₄a+n. Also find the solution of the relation with initial condition a₀ 1.

    10
  3. 3.

    Define spanning tree and minimum spanning tree with suitable example. Use Kruskal's algorithms to find minimum spanning tree in the given graph.

    10

Group B

Attempt any Eight questions(8 × 5 = 40)

  1. 4.

    What is tautology? Show (p ∧ q)→(p ∨ q) is a tautology.

    5
  2. 5.

    Define cartesian product. Find A3 for the set A = (a, b, c).

    5
  3. 6.

    How can you represent relations using matrices? Suppose that A= {1, 2, 3} and B= {1, 2}. Let R be the relation from A to B containing (a, b) if a ∈A, b ∈B, and a > b. What matrix representing R if a1 = 1, a2 = 2, a3 = 3, and b1 = 1 and b2 = 2?

    5
  4. 7.

    Use mathematical induction to show that the sum of first n positive integers is n(n+1)/2.

    5
  5. 8.

    What is congruent modulo? Determine whether 20 is congruent to 8 modulo 6 and 25 is congruent to 17 modulo 5.

    5
  6. 9.

    Explain trial division with example? Using trial division, show that 101 is prime.

    5
  7. 10.

    Explain product rule. How many strings are there of four lowercase letters that have the letter x in them?

    5
  8. 11.

    What is graph? Explain simple graph and pseudograph with example.

    5
  9. 12.

    What is Euler path? Compare it with Hamilton path.

    5

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