Tribhuwan University

Institute of Science and Technology

Model

Bachelor Level / First Year / Second Semester / Science

Bachelors in Information Technology (BIT152)

(Discrete Structure)

Full Marks: 60

Pass Marks: 24

Time: 3 Hours

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

The figures in the margin indicate full marks.

Section A

Long Answers Questions

Attempt any TWO questions.
[2*10=20]
1.
Explain mathematical induction. Use mathematical induction to prove that the sum of the first n odd positive integers is $n^2$. What is recursively defined function?[10]
2.
Define recurrence relation. What do you mean by linear homogeneous recurrence of degree \( k \) with constant coefficients? What is the solution of the recurrence relation \( a_n = a_{n-1} + a_{n-2} \) with initial conditions \( a_0 = 0 \) and \( a_1 = 1 \)?[10]
3.
What is shortest path finding problem? Use Dijkstra's algorithm to find the length of the shortest path between a and z in the given weighted graphs.
question image
[10]
Section B

Short Answers Questions

Attempt any Eight questions.
[8*5=40]
4.
What do you mean by converse, inverse, and contrapositive? Show that the sentences "if it is hot today then today is Sunday" and "if it is not Sunday then today is not hot" are logically equivalent. [5]
5.
What direct proof? Give a direct proof of the theorem "If n is an odd integer, then $n^2$ is an odd integer." [5]
6.
Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}. Use bit strings to find the union and intersection of the sets {1, 2, 3, 4, 5} and {1, 3, 5, 7, 9}. [5]
7.
Define celling and floor function. Explain Boolean function with example. [5]
8.
How can we represent a relation using directed graph? Draw a directed graph of the relation R = {(1, 1), (1, 3), (2, 1), (2, 3), (2, 4), (3, 1), (3, 2), (4, 1)} on the set {1, 2, 3, 4}. [5]
9.
Explain Euclidean algorithm. Use Euclidean algorithm to find the greatest common divisor of 414 and 662. [5]
10.
Differentiate permutation with combination. What is the next permutation in lexicographic order after 362541? [5]
11.
How can we represent a graph using Adjacency Matrix? Explain. [5]
12.
Define spanning tree. Explain minimum spanning tree with example. [5]