CSC165 Discrete Structure

Discrete Structure TU Board 2076 question paper

12 questionsSit this paper (timed)

Tribhuvan University

Bachelor of Science in Computer Science and Information Technology

Semester 2 · TU Board 2076

Course Title: Discrete Structure (CSC165)

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

Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.

Group A

(2 × 10 = 20)

  1. 1.

    State pigeonhole principle. Solve the recurrence relation a_n = 3a_n-1 – 3a_n-2 + a_n-3 with initial conditions a_0=1 ,a_1 = 3, a_2=7.

    10
  2. 2.

    Find the value of x such that x = 1 (mod 3), x = 1 (mod 4), x = 1 (mod 5) and x = 0 (mod 7) using Chinese remainder theorem.

    10
  3. 3.

    Define Euler circuit with suitable example. Find the maximal flow s to t from the given network flow.

    [figure in the original paper]

    10

Group B

(8 × 5 = 40)

  1. 4.

    Prove that for every positive integer n ≥ 1, n^2+n is even integer using mathematical induction.

    5
  2. 5.

    All over smart people are stupid. Children of stupid people are naughty. John is a children of Jane. Jane is over smart. Represent these statements in FOPL and prove that John is naughty.

    5
  3. 6.

    Which of the following are possets?

    1. (Z, =)
    2. (Z, ≠)
    3. (Z, ⊆)
    5
  4. 7.

    Define reflexive closure and symmetric closure. Find the remainder when 4x^2 – x + 3 is divided by x + 2 using remainder theorem.

    5
  5. 8.

    Define Euler path and Hamilton path. Give examples of both Euler and Hamilton path.

    5
  6. 9.

    How many 3 digits numbers can be formed from the digits 1,2,3,4 and 5 assuming that:

    1. Repetitions of digits are allowed
    2. Repetitions of digits are not allowed
    5
  7. 10.

    What is minimum spanning tree? Explain Kruskal's algorithm for finding minimum spanning tree.

    5
  8. 11.

    List any two applications of graph coloring theorem. Prove that "A tree with n vertices has n-1 edges"

    5
  9. 12.

    Define ceiling and floor function. Why do we need Inclusion – Exclusion principle? Make it clear with suitable example.

    5

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