Discrete Structure (CSC165) 2080 BS Past Questions & Solutions

Tribhuvan University (TU) 2080 BS board exam question paper with verified step-by-step solutions for BSc CSIT Second Semester.

TRIBHUVAN UNIVERSITY

INSTITUTE OF SCIENCE AND TECHNOLOGY

2080 B.S.

Bachelor Level: B.Sc. CSIT

Semester: Second Semester

Subject: Discrete Structure (CSC165)

Full Marks: 60 / 80

Pass Marks: 24 / 32

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

Group A

Long Answer Questions

Attempt any Two questions.

  1. 1
    How can you use mathematical induction to prove statements? Use mathematical induction to show that the sum of first n positive integers is n(n+1)/2. (4+6)
  2. 2
    Explain linear homogeneous recurrence relation with constant coefficients. What is the solution of the recurrence relation a_n = 6a_(n-1) - 9a_(n-2) with initial conditions a_0 = 1 and a_1 = 6? (2+8)
  3. 3
    What is shortest path problem? Use Dijkstra's shortest path algorithm to find the shortest path between the vertices a and z in the weighted graph given below. (2+8)
    Discrete Structure 2080 Question 3

Group B

Short Answer Questions

Attempt any Eight questions.

  1. 4
    Let us assume that R be a relation on the set of ordered pairs of positive integers such that ((a,b),(c,d)) ∈ R if and only if ad=bc. Is R an equivalence relation? (5)
  2. 5
    Define function. Let f1 and f2 be functions from R to R such that f1(x) = x^2 and f2(x) = x - x^2. What are the functions f1+f2 and f1*f2? (2+3)
  3. 6
    Explain fuzzy set with example. How do you find complement of a fuzzy set? (2.5+2.5)
  4. 7
    What is congruent modulo? Determine whether 37 is congruent to 3 modulo 7 and whether -29 is congruent to 5 modulo 17. (2+1.5+1.5)
  5. 8
    Define network flow with example. What are saturated edge, unsaturated edge and slack value? (2+3)
  6. 9
    Give an example of tautology and contradiction. Show that implication and contrapositive are equivalence. (2+3)
  7. 10
    What is direct proof? Give a direct proof that if m and n are both perfect squares, then mn is also a perfect square. (1.5+3.5)
  8. 11
    What is product rule? How many strings are there of four lowercase letters that have the letter x in them? (1.5+3.5)
  9. 12
    Explain matrix representation of relations with example. (5)