Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option/answer the following (Any seven question
only):
The function $ f:R \rightarrow R $ defined by $ f(x)=x^3+5 $
Consider the following relation R on a set $ A=\{1,2,3,4\} $: R = {(1,1), (1, 3), (3, 2), (2, 2), (3, 3), (3, 1), (2, 3), (1, 4), (4, 4)} Then
Out of the following which of these integers is not prime?
The Greatest common divisor of 0 and 11
Suppose G is a group with a binary operation * defined by $ a*b=a+b+1 $, for $ a, b \in G $ then
The field which contains at least _____ element/elements
The set of integers with respect to addition is
The total number of edges in a complete graph of n vertices is
In any undirected graph, the sum of degrees of all vertices
$ (p \rightarrow q) \wedge (r \rightarrow q) $ is equivalent to
Q.2 Solve both questions :
Given $ A=\{1,2,3\} $, $ B=\{7,8\} $ and $ R=\{(1,7), (2, 7), (1, 8), (3, 8)\} $, find $ R^{-1} $ (inverse of R) and $ R' $ complement of R.
Consider $ A=B=C=R $ set of real numbers and let $ f:A \rightarrow B $, $ g: B \rightarrow C $ defined by $ f(x)=x+9 $ and $ g(y)=y^2+3 $ find the following composition functions: $ (f \circ g)(a) $, $ (g \circ f)(a) $, $ (g \circ f)(x) $, $ (f \circ g)(-3) $.
Q.3 Solve both questions :
What is the negation of each of the following propositions? (i) Today is Tuesday (ii) A cow is an animal (iii) No one wants to buy my house
Determine the truth value of each of the following statements (i) $ 4+3=7 $ and $ 6+2=8 $ (ii) $ 2+3=4 $ and $ 3+1=2 $
Q.4 Solve both questions :
Show that the set of rational numbers Q forms an abelian group.
Define a ring, give an example of a commutative ring without zero divisors and a non-commutative ring with identity.
Q.5 Solve both questions :
Describe the Fundamental Theorem of Arithmetic. Factorize the number '324' and represent it as a product of primes.
Use the Euclidean algorithm to find the greatest common divisor of each pair of integers, (i) 60, 90 (ii) 414, 662
Q.6 Solve both questions :
Describe a graph model that can be used to represent all forms of electronic communication between two people in a single graph. What kind of graph is needed?
Explain the complete graph and prove that $ k_5 $ (complete graph) is a nonplanar graph.
Q.7 Solve both questions :
Explain the congruence relation. Let $ n $ be a positive integer then: (i) If $ a \equiv b \pmod{n} $, then $ b \equiv a \pmod{n} $ (ii) If $ a \equiv b \pmod{n} $ and $ b \equiv c \pmod{n} $, then $ a \equiv c \pmod{n} $.
Show that $ p \Leftrightarrow q \equiv (p \Rightarrow q) \wedge (q \Rightarrow p) $
Q.8 Solve both questions :
Write short notes of the following: (i) Eulerian Graph (ii) Graph Coloring
Write short notes of the following: (i) Chromatic number (ii) Perfect Graph
Q.9 Solve both questions :
What is the field? Show that $ (Q, +, \times) $ is a field.
If in a ring R with $ (xy)^2=x^2y^2 $ for all $ x, y \in R $, then R is commutative.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option/answer the following (Any seven question
only):
The function $ f:R \rightarrow R $ defined by $ f(x)=x^3+5 $
Consider the following relation R on a set $ A=\{1,2,3,4\} $: R = {(1,1), (1, 3), (3, 2), (2, 2), (3, 3), (3, 1), (2, 3), (1, 4), (4, 4)} Then
Out of the following which of these integers is not prime?
The Greatest common divisor of 0 and 11
Suppose G is a group with a binary operation * defined by $ a*b=a+b+1 $, for $ a, b \in G $ then
The field which contains at least _____ element/elements
The set of integers with respect to addition is
The total number of edges in a complete graph of n vertices is
In any undirected graph, the sum of degrees of all vertices
$ (p \rightarrow q) \wedge (r \rightarrow q) $ is equivalent to
Q.2 Solve both questions :
Given $ A=\{1,2,3\} $, $ B=\{7,8\} $ and $ R=\{(1,7), (2, 7), (1, 8), (3, 8)\} $, find $ R^{-1} $ (inverse of R) and $ R' $ complement of R.
Consider $ A=B=C=R $ set of real numbers and let $ f:A \rightarrow B $, $ g: B \rightarrow C $ defined by $ f(x)=x+9 $ and $ g(y)=y^2+3 $ find the following composition functions: $ (f \circ g)(a) $, $ (g \circ f)(a) $, $ (g \circ f)(x) $, $ (f \circ g)(-3) $.
Q.3 Solve both questions :
What is the negation of each of the following propositions? (i) Today is Tuesday (ii) A cow is an animal (iii) No one wants to buy my house
Determine the truth value of each of the following statements (i) $ 4+3=7 $ and $ 6+2=8 $ (ii) $ 2+3=4 $ and $ 3+1=2 $
Q.4 Solve both questions :
Show that the set of rational numbers Q forms an abelian group.
Define a ring, give an example of a commutative ring without zero divisors and a non-commutative ring with identity.
Q.5 Solve both questions :
Describe the Fundamental Theorem of Arithmetic. Factorize the number '324' and represent it as a product of primes.
Use the Euclidean algorithm to find the greatest common divisor of each pair of integers, (i) 60, 90 (ii) 414, 662
Q.6 Solve both questions :
Describe a graph model that can be used to represent all forms of electronic communication between two people in a single graph. What kind of graph is needed?
Explain the complete graph and prove that $ k_5 $ (complete graph) is a nonplanar graph.
Q.7 Solve both questions :
Explain the congruence relation. Let $ n $ be a positive integer then: (i) If $ a \equiv b \pmod{n} $, then $ b \equiv a \pmod{n} $ (ii) If $ a \equiv b \pmod{n} $ and $ b \equiv c \pmod{n} $, then $ a \equiv c \pmod{n} $.
Show that $ p \Leftrightarrow q \equiv (p \Rightarrow q) \wedge (q \Rightarrow p) $
Q.8 Solve both questions :
Write short notes of the following: (i) Eulerian Graph (ii) Graph Coloring
Write short notes of the following: (i) Chromatic number (ii) Perfect Graph
Q.9 Solve both questions :
What is the field? Show that $ (Q, +, \times) $ is a field.
If in a ring R with $ (xy)^2=x^2y^2 $ for all $ x, y \in R $, then R is commutative.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Write the answer of the following (Any seven question
only):
Let A be the set odd positive integers less than 10. Then cardinality of A, |A| is
If m is the number of objects (pigeons) and n is the number of boxes (pigeonholes), then the function is both one-to-one and onto if
If $ A \times B = B \times A $, (Where A and B are general matrices) then
A partial ordered relation is transitive, reflexive and
If B is a Boolean Algebra, then which of the following is true
$ P \rightarrow q $ is logically equivalent to
If $ f(x) = \cos x $ and $ g(x) = x^3 $ then $ (f \circ g)(x) $ is
The number of distinguishable permutations of the letters in the word BANANA are
Which of the following pair is not congruent modulo 7?
Let $ N=\{1,2,3,........\} $ be ordered by divisibility, which of the following subset is totally ordered
Q.2 Solve both questions :
Let $ A = B = \{x | -1 \le x \le 1\} $ for each of the following functions state where it is injective, surjective or bijective: i) $ g(x) = \sin \pi x $ ii) $ b(x) = \frac{2x}{3} $
Let $ f(x) = x+2 $, $ g(x) = x-2 $, $ h(x) = 3x $ find (i) $ f \circ g $ (ii) $ f \circ g \circ h $
Q.3 Solve both questions :
Find the power set of each of these sets: i) $ \{a,b\} $ ii) $ \{\phi, \{\phi\}\} $
Use Cantor's diagonal argument to prove that set F of all functions $ f: (0,1) \rightarrow R $ has larger Cardinality than |R|.
Q.4 Solve this question :
Determine if the sets are countable or uncountable: a.) the set A of all function $ g: Z_{+} \rightarrow Z_{+} $ b.) The set B of all functions $ f: Z_{+} \rightarrow \{0,1\} $
Q.5 Solve this question :
Prove the following by using the principle of mathematical induction for all $ n \in N $: $ 1^3 + 2^3 + 3^3 + \dots + n^3 = \left(\frac{n(n+1)}{2}\right)^2 $
Q.6 Solve this question :
State and prove Division algorithm theorem well-ordering principle.
Q.7 Solve both questions :
Check the validity of the following argument all integers are rational numbers. Some integers are powers of 5. Therefore, some rational numbers are powers of 5.
A grocery store employee is stocking apples. Each apple is a different color. There are 10 apples left in the box and the employee pulls out 2 of them at random. What is the probability that the employee pulls out one pink apple and yellow apple?
Q.8 Solve this question :
Let $ \Psi: G \rightarrow H $ be a homomorphism of groups. Show that if $ a \in G $ has order n, then $ \Psi(a) \in H $ has order dividing n.
Q.9 Solve both questions :
Consider the given graph. (a) Does a Hamiltonian path exist? If so describe it. If not say why not.
(b) Does an Eulerian path exist? If so describe it. If not say why not.

Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Write the answer of the following (Any seven question
only):
Let A be the set odd positive integers less than 10. Then cardinality of A, |A| is
If m is the number of objects (pigeons) and n is the number of boxes (pigeonholes), then the function is both one-to-one and onto if
If $ A \times B = B \times A $, (Where A and B are general matrices) then
A partial ordered relation is transitive, reflexive and
If B is a Boolean Algebra, then which of the following is true
$ P \rightarrow q $ is logically equivalent to
If $ f(x) = \cos x $ and $ g(x) = x^3 $ then $ (f \circ g)(x) $ is
The number of distinguishable permutations of the letters in the word BANANA are
Which of the following pair is not congruent modulo 7?
Let $ N=\{1,2,3,........\} $ be ordered by divisibility, which of the following subset is totally ordered
Q.2 Solve both questions :
Let $ A = B = \{x | -1 \le x \le 1\} $ for each of the following functions state where it is injective, surjective or bijective: i) $ g(x) = \sin \pi x $ ii) $ b(x) = \frac{2x}{3} $
Let $ f(x) = x+2 $, $ g(x) = x-2 $, $ h(x) = 3x $ find (i) $ f \circ g $ (ii) $ f \circ g \circ h $
Q.3 Solve both questions :
Find the power set of each of these sets: i) $ \{a,b\} $ ii) $ \{\phi, \{\phi\}\} $
Use Cantor's diagonal argument to prove that set F of all functions $ f: (0,1) \rightarrow R $ has larger Cardinality than |R|.
Q.4 Solve this question :
Determine if the sets are countable or uncountable: a.) the set A of all function $ g: Z_{+} \rightarrow Z_{+} $ b.) The set B of all functions $ f: Z_{+} \rightarrow \{0,1\} $
Q.5 Solve this question :
Prove the following by using the principle of mathematical induction for all $ n \in N $: $ 1^3 + 2^3 + 3^3 + \dots + n^3 = \left(\frac{n(n+1)}{2}\right)^2 $
Q.6 Solve this question :
State and prove Division algorithm theorem well-ordering principle.
Q.7 Solve both questions :
Check the validity of the following argument all integers are rational numbers. Some integers are powers of 5. Therefore, some rational numbers are powers of 5.
A grocery store employee is stocking apples. Each apple is a different color. There are 10 apples left in the box and the employee pulls out 2 of them at random. What is the probability that the employee pulls out one pink apple and yellow apple?
Q.8 Solve this question :
Let $ \Psi: G \rightarrow H $ be a homomorphism of groups. Show that if $ a \in G $ has order n, then $ \Psi(a) \in H $ has order dividing n.
Q.9 Solve both questions :
Consider the given graph. (a) Does a Hamiltonian path exist? If so describe it. If not say why not.
(b) Does an Eulerian path exist? If so describe it. If not say why not.

Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer of the following (any seven):
The statement $ (\sim P \leftrightarrow Q) \wedge \sim Q $ is true, when
Which of the following statements regarding sets is false?
What is the induction hypothesis assumption for the inequality $ m! > 2^m $ where $ m \ge 4 $?
A simple graph can have
An undirected graph has 8 vertices labelled 1, 2, ..., 8 and 31 edges. Vertices 1, 3, 5, 7 have degree 8 and vertices 2, 4, 6, 8 have degree 7. What is the degree of vertex 8?
A graph which has the same number of edges as its complement must have number of vertices congruent to ___ or ___ modulo 4 (for integral values of number of edges).
A graph which consists of disjoint union of trees is called
Which of the following two sets are equal?
If $ C_n $ is the nth cyclic graph, where $ n > 3 $ and n is odd, determine the value of $ X(C_n) $
The number of edges in a regular graph of degree 46 and 8 vertices is
Q.2 Solve both questions :
Let $ D = \{-48, -14, -8, 0, 1, 3, 16, 23, 26, 32, 36\} $. Determine which of the following
statements are true and which are false. Provide counterexamples for those statements that are
false.
(i) $ \forall x \in D $, if x is odd, then $ x > 0 $
(ii) $ \forall x \in D $, if x is less than 0, then x is even
(iii) $ \forall x \in D $, if x is even, then $ x \le 0 $
Indicate which of the following statements are true and which are false. Justify your answers as
best
you can:
(i) $ \forall x \in Z^+ $, $ \exists y \in Z^+ $ such that $ x = y + 1 $
(ii) $ \forall x \in Z $, $ \exists y \in Z $ such that $ x = y + 1 $
(iii) $ \exists x \in R $ such that $ \forall y \in R $, $ x = y + 1 $
(iv) $ \forall x \in R^+ $, $ \exists y \in R^+ $ such that $ xy = 1 $
(v) $ \forall x \in R $, $ \exists y \in R $ such that $ xy = 1 $
(vi) $ \forall x \in Z^+ $ and $ \forall y \in Z^+ $ $ \exists z \in Z^+ $
such
that $ z = x - y $
(vii) $ \forall x \in Z $ and $ \forall y \in Z $, $ \exists z \in Z $ such
that
$ z = x - y $
(viii) $ \exists u \in R^+ $ such that $ \forall v \in R^+ $, $ uv < v $
Q.3 Solve both questions :
Prove the following:
(i) There is a real number x such that $ x > 1 $ and $ 2^x > x^{10} $.
(ii) There is an integer n such that $ 2n^2 - 5n + 2 $ is prime.
Disprove that for all real numbers a and b, if $ a < b $, then $ a^2 < b^2 $.
Q.4 Solve all three questions :
Show that $ p \vee (q \wedge r) $ and $ (p \vee q) \wedge (p \vee r) $ are logically equivalent. This is the distributive law of disjunction over conjunction.
Find the greatest common divisor of 414 and 662 using the Euclidean algorithm.
If a and b are positive integers, then prove that there exists integers s and t such that $ gcd(a,b) = sa + tb $.
Q.5 Solve both questions :
Use mathematical induction to prove this formula for the sum of a finite number of terms of a
geometric progression with initial term a and common ratio r:
$ \sum_{j=0}^{n} ar^j = a + ar + ar^2 + \cdots + ar^n = \frac{ar^{n+1}-a}{r-1} $ when $
r
\ne 1 $, where n is a non-negative integer.
Write short notes on the following:
(i) Forward proof
(ii) Disjunctive and conjunctive normal form
(iii) Fundamental theorem of arithmetic
Q.6 Solve both questions :
An odd number of people stand in a yard at mutually distinct distances. At the same time each person throws a pie at their nearest neighbour, hitting this person. Use mathematical induction to show that there is at least one survivor, that is, at least one person who is not hit by a pie.
Prove Bernoulli's inequality that if $ h > -1 $, then $ 1 + nh \le (1 + h)^n $ for all non-negative integers n.
Q.7 What is pigeonhole principle? Using it, prove the
following:
What is pigeonhole principle? Using it, prove the
following:
During a month with 30 days, a baseball team plays at least one game a day, but no
more than 45
games. Show that there must be a period of some number of consecutive days during which the team
must play exactly 14 games.
What is pigeonhole principle? Using it, prove the
following:
The sequence 8, 11, 9, 1, 4, 6, 12, 10, 5, 7 contains 10 terms. Note that $ 10 =
3^2 + 1 $.
There
are four strictly increasing subsequences of length four, namely, 1, 4, 6, 12; 1, 4, 6, 7; 1, 4,
6,
10; and 1, 4, 5, 7. There is also a strictly decreasing subsequence of length four, namely, 11,
9,
6, 5.
Q.8 Solve all questions :
In a Round-Robin tournament, the Tigers beat the Blue Jays, the Tigers beat the Cardinals, the Tigers beat the Orioles, the Blue Jays beat the Cardinals, the Blue Jays beat the Orioles and the Cardinals beat the Orioles. Model this outcome with a directed graph.
Let $ G=(V,E) $ be a simple graph. Let R be the relation on V consisting of pairs of vertices (u, v) such that there is a path from u to v or such that $ u = v $. Show that R is an equivalence relation.
Determine whether the following given pair of directed graphs, shown in Fig. 1 and Fig. 2, are isomorphic or not. Exhibit an isomorphism or provide a rigorous argument that none exists.

Q.9 Solve all questions :
Use pseudocode to describe an algorithm for determining the value of a game tree when both players follow a minmax strategy.
Suppose that $ T_1 $ and $ T_2 $ are spanning trees of a simple graph G. Moreover, suppose that $ e_1 $ is an edge in $ T_1 $ that is not in $ T_2 $. Show that there is an edge $ e_2 $ in $ T_2 $ that is not in $ T_1 $ such that $ T_1 $ remains a spanning tree if $ e_1 $ is removed from it and $ e_2 $ is added to it, and $ T_2 $ remains a spanning tree if $ e_2 $ is removed from it and $ e_1 $ is added to it.
Show that a degree-constrained spanning tree of a simple graph in which each vertex has degree not exceeding 2 consists of a single Hamiltonian path in the graph.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer of the following (any seven):
The statement $ (\sim P \leftrightarrow Q) \wedge \sim Q $ is true, when
Which of the following statements regarding sets is false?
What is the induction hypothesis assumption for the inequality $ m! > 2^m $ where $ m \ge 4 $?
A simple graph can have
An undirected graph has 8 vertices labelled 1, 2, ..., 8 and 31 edges. Vertices 1, 3, 5, 7 have degree 8 and vertices 2, 4, 6, 8 have degree 7. What is the degree of vertex 8?
A graph which has the same number of edges as its complement must have number of vertices congruent to ___ or ___ modulo 4 (for integral values of number of edges).
A graph which consists of disjoint union of trees is called
Which of the following two sets are equal?
If $ C_n $ is the nth cyclic graph, where $ n > 3 $ and n is odd, determine the value of $ X(C_n) $
The number of edges in a regular graph of degree 46 and 8 vertices is
Q.2 Solve both questions :
Let $ D = \{-48, -14, -8, 0, 1, 3, 16, 23, 26, 32, 36\} $. Determine which of the following
statements are true and which are false. Provide counterexamples for those statements that are
false.
(i) $ \forall x \in D $, if x is odd, then $ x > 0 $
(ii) $ \forall x \in D $, if x is less than 0, then x is even
(iii) $ \forall x \in D $, if x is even, then $ x \le 0 $
Indicate which of the following statements are true and which are false. Justify your answers as
best
you can:
(i) $ \forall x \in Z^+ $, $ \exists y \in Z^+ $ such that $ x = y + 1 $
(ii) $ \forall x \in Z $, $ \exists y \in Z $ such that $ x = y + 1 $
(iii) $ \exists x \in R $ such that $ \forall y \in R $, $ x = y + 1 $
(iv) $ \forall x \in R^+ $, $ \exists y \in R^+ $ such that $ xy = 1 $
(v) $ \forall x \in R $, $ \exists y \in R $ such that $ xy = 1 $
(vi) $ \forall x \in Z^+ $ and $ \forall y \in Z^+ $ $ \exists z \in Z^+ $
such
that $ z = x - y $
(vii) $ \forall x \in Z $ and $ \forall y \in Z $, $ \exists z \in Z $ such
that
$ z = x - y $
(viii) $ \exists u \in R^+ $ such that $ \forall v \in R^+ $, $ uv < v $
Q.3 Solve both questions :
Prove the following:
(i) There is a real number x such that $ x > 1 $ and $ 2^x > x^{10} $.
(ii) There is an integer n such that $ 2n^2 - 5n + 2 $ is prime.
Disprove that for all real numbers a and b, if $ a < b $, then $ a^2 < b^2 $.
Q.4 Solve all three questions :
Show that $ p \vee (q \wedge r) $ and $ (p \vee q) \wedge (p \vee r) $ are logically equivalent. This is the distributive law of disjunction over conjunction.
Find the greatest common divisor of 414 and 662 using the Euclidean algorithm.
If a and b are positive integers, then prove that there exists integers s and t such that $ gcd(a,b) = sa + tb $.
Q.5 Solve both questions :
Use mathematical induction to prove this formula for the sum of a finite number of terms of a
geometric progression with initial term a and common ratio r:
$ \sum_{j=0}^{n} ar^j = a + ar + ar^2 + \cdots + ar^n = \frac{ar^{n+1}-a}{r-1} $ when $
r
\ne 1 $, where n is a non-negative integer.
Write short notes on the following:
(i) Forward proof
(ii) Disjunctive and conjunctive normal form
(iii) Fundamental theorem of arithmetic
Q.6 Solve both questions :
An odd number of people stand in a yard at mutually distinct distances. At the same time each person throws a pie at their nearest neighbour, hitting this person. Use mathematical induction to show that there is at least one survivor, that is, at least one person who is not hit by a pie.
Prove Bernoulli's inequality that if $ h > -1 $, then $ 1 + nh \le (1 + h)^n $ for all non-negative integers n.
Q.7 What is pigeonhole principle? Using it, prove the
following:
What is pigeonhole principle? Using it, prove the
following:
During a month with 30 days, a baseball team plays at least one game a day, but no
more than 45
games. Show that there must be a period of some number of consecutive days during which the team
must play exactly 14 games.
What is pigeonhole principle? Using it, prove the
following:
The sequence 8, 11, 9, 1, 4, 6, 12, 10, 5, 7 contains 10 terms. Note that $ 10 =
3^2 + 1 $.
There
are four strictly increasing subsequences of length four, namely, 1, 4, 6, 12; 1, 4, 6, 7; 1, 4,
6,
10; and 1, 4, 5, 7. There is also a strictly decreasing subsequence of length four, namely, 11,
9,
6, 5.
Q.8 Solve all questions :
In a Round-Robin tournament, the Tigers beat the Blue Jays, the Tigers beat the Cardinals, the Tigers beat the Orioles, the Blue Jays beat the Cardinals, the Blue Jays beat the Orioles and the Cardinals beat the Orioles. Model this outcome with a directed graph.
Let $ G=(V,E) $ be a simple graph. Let R be the relation on V consisting of pairs of vertices (u, v) such that there is a path from u to v or such that $ u = v $. Show that R is an equivalence relation.
Determine whether the following given pair of directed graphs, shown in Fig. 1 and Fig. 2, are isomorphic or not. Exhibit an isomorphism or provide a rigorous argument that none exists.

Q.9 Solve all questions :
Use pseudocode to describe an algorithm for determining the value of a game tree when both players follow a minmax strategy.
Suppose that $ T_1 $ and $ T_2 $ are spanning trees of a simple graph G. Moreover, suppose that $ e_1 $ is an edge in $ T_1 $ that is not in $ T_2 $. Show that there is an edge $ e_2 $ in $ T_2 $ that is not in $ T_1 $ such that $ T_1 $ remains a spanning tree if $ e_1 $ is removed from it and $ e_2 $ is added to it, and $ T_2 $ remains a spanning tree if $ e_2 $ is removed from it and $ e_1 $ is added to it.
Show that a degree-constrained spanning tree of a simple graph in which each vertex has degree not exceeding 2 consists of a single Hamiltonian path in the graph.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer (any seven):
The statement $ p \rightarrow q $ is logically equivalent to
The contrapositive of the conditional statement $ p \rightarrow q $ is
If A and B are two nonempty sets having n elements in common, then $ A \times B $ and $ B \times A $ will have how many elements in common?
If a set A have n elements, then how many relations will be there on set A?
If $ P(\phi) $ represents the power set of $ \phi $, then $ n(P(P(P(\phi)))) $ equal to
The number of edges in a bipartite graph with n vertices is at most
If $ (S, *) $ is a monoid, where $ S = \{1, 2, 3, 6\} $ is defined by $ a * b = \text{lcm}(a, b) $, and where $ a, b \in S $, then the identity element is
The total number of subgroups of a group G of prime order is
For the poset $ \{3, 5, 9, 15, 24, 45\} $; divisor of the glb of $ \{3, 5\} $ is
The number of pendant vertices of a full-binary tree is
Q.2 Solve both questions :
Using truth table, show that-
(i) $ ((p \rightarrow (q \rightarrow r))) \rightarrow ((p \rightarrow q) \rightarrow (p
\rightarrow r)) $ is a tautology.
(ii) $ \sim(q \rightarrow r) \wedge r \wedge (p \rightarrow q) $ is a contradiction.
Obtain the principal disjunctive normal form (PDNF) and principal conjunctive normal form (PCNF) of the statement $ (p \rightarrow (q \wedge r)) \wedge (\sim p \rightarrow (\sim q \wedge \sim r)) $.
Q.3 Solve both questions :
For any sets A and B, prove that
(i) $ (A \cup B)' = A' \cap B' $;
(ii) $ (A \cap B)' = A' \cup B' $.
If two sets A and B have n elements in common, then show that the sets $ A \times B $ and $ B \times A $ will have $ 2^n $ elements in common.
Q.4 Solve both questions :
If R is the relation on the set of positive integers, such that $ (a, b) \in R $ if and only if $ a^2 + b $ is even, prove that R is an equivalence relation.
Define partition of a set. If the relation R on the set of integers Z is defined by $ a R b $ iff $ a \cong b \pmod 4 $, find the partition induced by R.
Q.5 Solve both questions :
If R and S be relations on $ A = \{1, 2, 3\} $ represented by the matrices $ M_R =
\begin{bmatrix} 1 & 0 & 1 \\ 0 & 1 & 0 \\ 0 & 0 & 0 \end{bmatrix} $ and $ M_S =
\begin{bmatrix} 0 & 1 & 1 \\ 1 & 1 & 0 \\ 0 & 0 & 1 \end{bmatrix} $.
Find the matrices that represent (i) $ R \cup S $, (ii) $ R \cap S $, (iii) $ R
\circ S
$, (iv) $ R - S $, (v) $ R' $, (vi) $ R \circ R $ and (vii) $ R \oplus S $.
Draw the Hasse diagram representing the partial ordering $ \{(A,B) : A \subseteq B\} $ on the power set $ P(S) $ where $ S = \{a,b,c\} $. Find the maximal, minimal, greatest and least elements of the poset.
Q.6 Solve both questions :
Define characteristic function of a set. If A and B are any two subsets of universal set U, then
show
that:
$ f_{A \cup B}(x) = f_A(x) + f_B(x) - f_{A \cap B}(x) $, for all $ x \in U $
If functions $ f, g, h: Z \rightarrow Z $ are defined as $ f(x) = x-1 $, $ g(x) = 3x
$
and $ h(x) = \begin{cases} 0, & \text{if x is even} \\ 1, & \text{if x is odd}
\end{cases}
$
Verify that $ f \circ (g \circ h) = (f \circ g) \circ h $.
Q.7 Solve both questions :
Show that every group of order 3 is cyclic.
Prove that the necessary and sufficient condition for a non-empty set H of a group (G, *) to be a subgroup is $ a, b \in H \Rightarrow a * b^{-1} \in H $.
Q.8 Solve both questions :
Show that the order of a subgroup of a finite group is a divisor of the order of the group.
Prove that the set S of all real numbers of the form $ a + b\sqrt{2} $ where a, b are integers is an integral domain with respect to usual addition and multiplication.
Q.9 Solve both questions :
Define adjacency matrix and incidence matrix of graph G. Draw the graph represented by the
adjacency
matrix
$ \begin{bmatrix} 0 & 1 & 1 & 1 \\ 1 & 0 & 1 & 0 \\ 1 & 1 & 0 & 0 \\ 1 & 0 & 0 & 0
\end{bmatrix} $
Show that a tree with n vertices has $ (n-1) $ edges.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer (any seven):
The statement $ p \rightarrow q $ is logically equivalent to
The contrapositive of the conditional statement $ p \rightarrow q $ is
If A and B are two nonempty sets having n elements in common, then $ A \times B $ and $ B \times A $ will have how many elements in common?
If a set A have n elements, then how many relations will be there on set A?
If $ P(\phi) $ represents the power set of $ \phi $, then $ n(P(P(P(\phi)))) $ equal to
The number of edges in a bipartite graph with n vertices is at most
If $ (S, *) $ is a monoid, where $ S = \{1, 2, 3, 6\} $ is defined by $ a * b = \text{lcm}(a, b) $, and where $ a, b \in S $, then the identity element is
The total number of subgroups of a group G of prime order is
For the poset $ \{3, 5, 9, 15, 24, 45\} $; divisor of the glb of $ \{3, 5\} $ is
The number of pendant vertices of a full-binary tree is
Q.2 Solve both questions :
Using truth table, show that-
(i) $ ((p \rightarrow (q \rightarrow r))) \rightarrow ((p \rightarrow q) \rightarrow (p
\rightarrow r)) $ is a tautology.
(ii) $ \sim(q \rightarrow r) \wedge r \wedge (p \rightarrow q) $ is a contradiction.
Obtain the principal disjunctive normal form (PDNF) and principal conjunctive normal form (PCNF) of the statement $ (p \rightarrow (q \wedge r)) \wedge (\sim p \rightarrow (\sim q \wedge \sim r)) $.
Q.3 Solve both questions :
For any sets A and B, prove that
(i) $ (A \cup B)' = A' \cap B' $;
(ii) $ (A \cap B)' = A' \cup B' $.
If two sets A and B have n elements in common, then show that the sets $ A \times B $ and $ B \times A $ will have $ 2^n $ elements in common.
Q.4 Solve both questions :
If R is the relation on the set of positive integers, such that $ (a, b) \in R $ if and only if $ a^2 + b $ is even, prove that R is an equivalence relation.
Define partition of a set. If the relation R on the set of integers Z is defined by $ a R b $ iff $ a \cong b \pmod 4 $, find the partition induced by R.
Q.5 Solve both questions :
If R and S be relations on $ A = \{1, 2, 3\} $ represented by the matrices $ M_R =
\begin{bmatrix} 1 & 0 & 1 \\ 0 & 1 & 0 \\ 0 & 0 & 0 \end{bmatrix} $ and $ M_S =
\begin{bmatrix} 0 & 1 & 1 \\ 1 & 1 & 0 \\ 0 & 0 & 1 \end{bmatrix} $.
Find the matrices that represent (i) $ R \cup S $, (ii) $ R \cap S $, (iii) $ R
\circ S
$, (iv) $ R - S $, (v) $ R' $, (vi) $ R \circ R $ and (vii) $ R \oplus S $.
Draw the Hasse diagram representing the partial ordering $ \{(A,B) : A \subseteq B\} $ on the power set $ P(S) $ where $ S = \{a,b,c\} $. Find the maximal, minimal, greatest and least elements of the poset.
Q.6 Solve both questions :
Define characteristic function of a set. If A and B are any two subsets of universal set U, then
show
that:
$ f_{A \cup B}(x) = f_A(x) + f_B(x) - f_{A \cap B}(x) $, for all $ x \in U $
If functions $ f, g, h: Z \rightarrow Z $ are defined as $ f(x) = x-1 $, $ g(x) = 3x
$
and $ h(x) = \begin{cases} 0, & \text{if x is even} \\ 1, & \text{if x is odd}
\end{cases}
$
Verify that $ f \circ (g \circ h) = (f \circ g) \circ h $.
Q.7 Solve both questions :
Show that every group of order 3 is cyclic.
Prove that the necessary and sufficient condition for a non-empty set H of a group (G, *) to be a subgroup is $ a, b \in H \Rightarrow a * b^{-1} \in H $.
Q.8 Solve both questions :
Show that the order of a subgroup of a finite group is a divisor of the order of the group.
Prove that the set S of all real numbers of the form $ a + b\sqrt{2} $ where a, b are integers is an integral domain with respect to usual addition and multiplication.
Q.9 Solve both questions :
Define adjacency matrix and incidence matrix of graph G. Draw the graph represented by the
adjacency
matrix
$ \begin{bmatrix} 0 & 1 & 1 & 1 \\ 1 & 0 & 1 & 0 \\ 1 & 1 & 0 & 0 \\ 1 & 0 & 0 & 0
\end{bmatrix} $
Show that a tree with n vertices has $ (n-1) $ edges.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer (any seven):
For any three sets A, B and C, which of the following statements is wrong?
Let A and B be two non-empty sets. Then the set of all ordered pairs (a, b), where $ a \in A $ and $ b \in B $ is called
If $ (a,a) \in R $ or equivalently $ a R a $, $ \forall a \in A $, then a relation R on a set A is called
Let A and B be finite sets with $ |A| = n $ and $ |B| = m $. How many functions are possible from A to B with A as the domain?
For the functions f and g defined by $ f(x) = x^3 $ and $ g(x) = x^2 + 1 \; \forall x \in R $, the value of $ (g \circ f)(x) $ is
A group G is said to be Abelian (or commutative) if for every
If $ f : G \rightarrow G' $ is a homomorphism, then which of the following it true?
For which of the following does there exist a tree satisfying the specified constraints?
For which of the following does there exist a graph $ G(V, E) $ satisfying the specified conditions?
The number of simple digraphs with $ |V| = 3 $ is
Q.2 Solve both questions :
Let $ f(x) = ax^2 + b $ and $ g(x) = cx^2 + d $, where a, b, c and d are constants. Determine for which constants a, b, c and d the following equation holds: $ f \circ g = g \circ f $
Show that the relation $ (x, y) R (a, b) $ such that $ x^2 + y^2 = a^2 + b^2 $ is an equivalence relation on the plane and describe the equivalence classes.
Q.3 Solve both questions :
Let $ (G, \cdot) $ be a group, where $ \cdot $ is usual multiplication operation on G.
Then
show that for any $ x, y \in G $ following equations hold:
(i) $ (x^{-1})^{-1} = x $
(ii) $ (xy)^{-1} = y^{-1}x^{-1} $
Construct the truth table for $ [(p \vee q) \wedge (p \rightarrow r) \wedge (q \rightarrow r)] \rightarrow r $. Also show that above statement is a tautology by developing a series of logical equivalences.
Q.4 Solve both questions :
If $ A = \{1, 2, 4\} $, $ B = \{2, 5, 7\} $ and $ C = \{1, 3, 7\} $, find $ (A \times B) \cup (A \times C) $.
List the ordered pairs in the relation R from $ A = \{1, 2, 3, 4\} $ to $ B = \{2, 3, 4,
5\} $, where $ (a, b) \in R $ if and only if-
(i) $ a = b $
(ii) $ a + b = 5 $
Q.5 Solve both questions :
Show that the set of integers with the composition $ \circ $ and * defined by $ a \circ b = a + b + 1 $ and $ a * b = ab + a + b $ is a ring.
State and prove Lagrange's theorem.
Q.6 Solve both questions :
Define a relation R on the set Z of all integers as follows: $ m R n \Leftrightarrow m+n $ is even for all $ m, n \in Z $. Is R a partial order relation? Prove or give a counter example.
Show that the group
(i) $ \{1, 2, 3, 4\}, X_5 $
(ii) $ \{1, 2, 3, 4, 5, 6\}, X_7 $
is cyclic.
Q.7 Solve both questions :
Let $ A = \{0, 1, 2, 3\} $, $ R = \{(x, y) : x+y=3\} $, $ S = \{(x, y) : 3|(x+y)\} $, $ T = \{(x, y) : \max(x,y)=3\} $. Compute (i) $ R \circ T $, (ii) $ T \circ R $ and (iii) $ S \circ S $.
In a group of 70 cars tested by a garage in Delhi, 15 had faulty tyres, 20 had faulty breaks and 18 exceeded the allowable emission limits. Also, 5 cars had faulty tyres and brakes, 6 failed on tyres and emission, 10 failed on brakes and emissions, and 4 cars were unsatisfactory in all three respects. How many cars had no faults in these three checks? Draw an appropriate Venn diagram.
Q.8 Solve both questions :
Define the vertex connectivity and edge connectivity of a graph. Prove that for a graph G with n vertices and e edges, vertex connectivity $ \le $ edge connectivity $ \le 2e/n $.
Define the adjacency matrix of a graph. Find the rank of the regular graph with n vertices and with degree $ p (< n) $ of every vertex.
Q.9 Write short notes on any three of the following:
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer (any seven):
For any three sets A, B and C, which of the following statements is wrong?
Let A and B be two non-empty sets. Then the set of all ordered pairs (a, b), where $ a \in A $ and is called
If or equivalently , , then a relation R on a set A is called
Let A and B be finite sets with and . How many functions are possible from A to B with A as the domain?
For the functions f and g defined by and $ g(x) = x^2 + 1 ; \forall x \in R (g \circ f)(x) $ is
A group G is said to be Abelian (or commutative) if for every
If is a homomorphism, then which of the following it true?
For which of the following does there exist a tree satisfying the specified constraints?
For which of the following does there exist a graph satisfying the specified conditions?
The number of simple digraphs with is
Q.2 Solve both questions :
Let and , where a, b, c and d are constants. Determine for which constants a, b, c and d the following equation holds:
Show that the relation such that is an equivalence relation on the plane and describe the equivalence classes.
Q.3 Solve both questions :
Let be a group, where is usual multiplication operation on G.
Then
show that for any following equations hold:
(i) $ (x^{-1})^{-1} = x $
(ii)
Construct the truth table for $ [(p \vee q) \wedge (p \rightarrow r) \wedge (q \rightarrow r)] \rightarrow r $. Also show that above statement is a tautology by developing a series of logical equivalences.
Q.4 Solve both questions :
If , and , find $ (A \times B) \cup (A \times C) $.
List the ordered pairs in the relation R from to $ B = {2, 3, 4,
5} (a, b) \in R $ if and only if-
(i) $ a = b $
(ii)
Q.5 Solve both questions :
Show that the set of integers with the composition and * defined by $ a \circ b = a + b + 1 a * b = ab + a + b $ is a ring.
State and prove Lagrange's theorem.
Q.6 Solve both questions :
Define a relation R on the set Z of all integers as follows: is even for all . Is R a partial order relation? Prove or give a counter example.
Show that the group
(i) $ {1, 2, 3, 4}, X_5 $
(ii) $ {1, 2, 3, 4, 5, 6}, X_7 $
is cyclic.
Q.7 Solve both questions :
Let , , $ S = {(x, y) : 3|(x+y)} T = {(x, y) : \max(x,y)=3} R \circ T T \circ R S \circ S $.
In a group of 70 cars tested by a garage in Delhi, 15 had faulty tyres, 20 had faulty breaks and 18 exceeded the allowable emission limits. Also, 5 cars had faulty tyres and brakes, 6 failed on tyres and emission, 10 failed on brakes and emissions, and 4 cars were unsatisfactory in all three respects. How many cars had no faults in these three checks? Draw an appropriate Venn diagram.
Q.8 Solve both questions :
Define the vertex connectivity and edge connectivity of a graph. Prove that for a graph G with n vertices and e edges, vertex connectivity edge connectivity .
Define the adjacency matrix of a graph. Find the rank of the regular graph with n vertices and with degree p (< n) of every vertex.
Q.9 Write short notes on any three of the following:
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose and write the correct option (any seven):
Let f and g be the functions defined by $ f(x) = 2x+3 $ and $ g(x) = 3x-2 $ then composition of f and g is
Among 200 people, 150 either swim or jog or both. If 85 swim and 60 swim and jog, how many jog?
A graph in which all nodes are of equal degree is known as graph.
The minimum number of spanning trees in a connected graph with n nodes is
If a set contains exactly m distinct elements where m denotes some non-negative integer, then the set is
In an unweighted, undirected-connected graph, the shortest path from a node S to every other node is computed most efficiently, in terms of time complexity, by
The negation of 'Today is Friday' is
Whether the relation R on the set of all integers is reflexive, symmetric, anti-symmetric, or transitive, where $ (x, y) \in R $ if and only if $ xy \ge 1 $?
If $ p = \text{'It is raining'} $ and $ q = \text{'She will go to college'} $, 'It is raining and she will not go to college' will be denoted by
If $ x > 0 $ and $ x^2 < 0 $, then $ x \ge 10 $.
Q.2 Solve both questions :
Define the following terms and give an example for each:
Reflexive relation, irreflexive relation, antisymmetric relation, partition set
Prove that, if $ S = \{s_1, s_2, \cdots, s_k\} $ be a set, then $ P(S) $ has $ 2^k $ elements.
Q.3 Solve this question :
Define 'group', 'order of a group', and 'Abelian group'. Prove that every subgroup of a cyclic group is cyclic.
Q.4 Solve both questions :
Define the following with example:
Ring, homomorphism, cyclic group, coset
Determine whether f is one-one or onto for the following cases:
(i) Let $ A = B = \{1, 2, 3, 4\} $ and $ f = \{(1, 1), (2, 3), (4, 2)\}
$
(ii) Let $ A = \{a, b, c\} $, $ B = \{1, 2, 3, 4\} $ and $ f = \{(a, 1), (b, 1),
(c,
4)\} $
Q.5 Solve both questions :
Suppose H and K are normal subgroups of G with $ H \cap K = \{1\} $. Show that $ xy = yx $ for all $ x \in H $ and $ y \in K $. Let $ I \in R $ be an ideal.
The radical $ \sqrt{I} = \{r \in R | rn \in I, n \in N\} $. Show that $ \sqrt{I} $ is an ideal.
Q.6 Solve both questions :
State and prove De Morgan's laws of set theory.
In a survey of 260 college students, the following data were obtained: 64 had taken a mathematics
course, 94 had taken a computer science course, 58 had taken a business course, 28 had taken
both a
mathematics and a business course, 26 had taken both a mathematics and a computer science
course, 22
had taken both a computer science and a business course, and 14 had taken all three types of
courses.
(i) How many of these students had taken none of the three courses?
(ii) How many had taken only a computer science course?
Q.7 Solve both questions :
Prove that for any non-empty binary tree T, if $ n_0 $ is the number of leaves and $ n_2 $ be the number of nodes having degree two, then $ n_0 = n_2 + 1 $.
Derive total number of nodes of a binary tree having depth n.
Q.8 Solve all questions :
What is graph? Differentiate between directed and undirected graph.
How many different ways can you represent a graph? Explain each of the representations by examples. What is complete graph?
Prove that the sum of degrees of all vertices in a graph is always even.
Q.9 Solve both questions :
Consider the graph given below:
(a) Find the adjacency list and BFS traversal of the above graph.
Prove that the maximum number of edges possible in a simple graph of n nodes is $ n(n-1)/2 $.

Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose and write the correct option (any seven):
Let f and g be the functions defined by $ f(x) = 2x+3 $ and $ g(x) = 3x-2 $ then composition of f and g is
Among 200 people, 150 either swim or jog or both. If 85 swim and 60 swim and jog, how many jog?
A graph in which all nodes are of equal degree is known as graph.
The minimum number of spanning trees in a connected graph with n nodes is
If a set contains exactly m distinct elements where m denotes some non-negative integer, then the set is
In an unweighted, undirected-connected graph, the shortest path from a node S to every other node is computed most efficiently, in terms of time complexity, by
The negation of 'Today is Friday' is
Whether the relation R on the set of all integers is reflexive, symmetric, anti-symmetric, or transitive, where $ (x, y) \in R $ if and only if $ xy \ge 1 $?
If $ p = \text{'It is raining'} $ and $ q = \text{'She will go to college'} $, 'It is raining and she will not go to college' will be denoted by
If $ x > 0 $ and $ x^2 < 0 $, then $ x \ge 10 $.
Q.2 Solve both questions :
Define the following terms and give an example for each:
Reflexive relation, irreflexive relation, antisymmetric relation, partition set
Prove that, if $ S = \{s_1, s_2, \cdots, s_k\} $ be a set, then $ P(S) $ has $ 2^k $ elements.
Q.3 Solve this question :
Define 'group', 'order of a group', and 'Abelian group'. Prove that every subgroup of a cyclic group is cyclic.
Q.4 Solve both questions :
Define the following with example:
Ring, homomorphism, cyclic group, coset
Determine whether f is one-one or onto for the following cases:
(i) Let $ A = B = \{1, 2, 3, 4\} $ and $ f = \{(1, 1), (2, 3), (4, 2)\}
$
(ii) Let $ A = \{a, b, c\} $, $ B = \{1, 2, 3, 4\} $ and $ f = \{(a, 1), (b, 1),
(c,
4)\} $
Q.5 Solve both questions :
Suppose H and K are normal subgroups of G with $ H \cap K = \{1\} $. Show that $ xy = yx $ for all $ x \in H $ and $ y \in K $. Let $ I \in R $ be an ideal.
The radical $ \sqrt{I} = \{r \in R | rn \in I, n \in N\} $. Show that $ \sqrt{I} $ is an ideal.
Q.6 Solve both questions :
State and prove De Morgan's laws of set theory.
In a survey of 260 college students, the following data were obtained: 64 had taken a mathematics
course, 94 had taken a computer science course, 58 had taken a business course, 28 had taken
both a
mathematics and a business course, 26 had taken both a mathematics and a computer science
course, 22
had taken both a computer science and a business course, and 14 had taken all three types of
courses.
(i) How many of these students had taken none of the three courses?
(ii) How many had taken only a computer science course?
Q.7 Solve both questions :
Prove that for any non-empty binary tree T, if $ n_0 $ is the number of leaves and $ n_2 $ be the number of nodes having degree two, then $ n_0 = n_2 + 1 $.
Derive total number of nodes of a binary tree having depth n.
Q.8 Solve all questions :
What is graph? Differentiate between directed and undirected graph.
How many different ways can you represent a graph? Explain each of the representations by examples. What is complete graph?
Prove that the sum of degrees of all vertices in a graph is always even.
Q.9 Solve both questions :
Consider the graph given below:
(a) Find the adjacency list and BFS traversal of the above graph.
Prove that the maximum number of edges possible in a simple graph of n nodes is $ n(n-1)/2 $.

Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option (any seven):
The set of all real numbers under the usual multiplication operation is not a group since
If $ R = \{(1, 2), (2, 3), (3, 3)\} $ be a relation defined on $ A = \{1, 2, 3\} $, then $ R \circ R $ is
Pick out the correct statement(s):
Let f and g be the functions defined by $ f(x) = 2x+3 $ and $ g(x) = 3x+2 $. Then the composition of f and g is
Among 200 people, 150 either swim or jog or both. If 85 swim and 60 swim and jog, then how many people jog?
If a graph is a tree, then
The relation R on the set of all integers, where $ (x, y) \in R $ if and only if $ xy \ge 1 $ is
How many functions are there from a set with three elements to a set with two elements?
Which one of the following is correct for any simple connected undirected graph with more than 2 vertices?
In an unweighted, undirected connected graph, the shortest path from a node S to every other node is computed most efficiently, in terms of time complexity, by
Q.2 Solve this question :
Define set. Let X be the universal set and $ S \subset X $, $ T \subset X $. Then prove
that:
(a) $ (S \cup T)^c = S^c \cap T^c $
(b) $ (S \cap T)^c = S^c \cup T^c $
Q.3 Solve both questions :
Define relations and function. What is equivalence relation?
Let A be the set of all people in India. If $ x, y \in A $, then let us say that $ (x,y) \in R $ if x and y have the same surname (i.e., last name). Then prove that R is an equivalence relation.
Q.4 Solve this question :
Define group, Abelian group and groupoid. Also define composition of functions. Let $ f: R \rightarrow \{x \in R: x \ge 0\} $ be given by $ f(x) = x^4 + x^2 + 6 $ and $ g: \{x \in R: x \ge 0\} \rightarrow R $ be given by $ g(x) = \sqrt{x} - 4 $. Then find $ (g \circ f)(x) $ and $ (f \circ g)(x) $.
Q.5 Solve both questions :
Suppose H and K are normal subgroups of G with $ H \cap K = \{1\} $. Show that $ xy = yx $ for all $ x \in H $ and $ y \in K $. Let $ I \in R $ be an ideal.
The radical $ \sqrt{I} = \{r \in R | rn \in I, n \in N\} $. Show that $ \sqrt{I} $ is an ideal.
Q.6 Solve this question :
Define commutative ring. Consider the set X, its power set $ P(X) = \{A | A \subset X\} $ is the set of all subsets of X. Show that the power set is a commutative ring under the following two operations $ A + B = (A - B) \cup (B - A) $ where $ \cup $ is set union and $ - $ is set difference, and $ AB = A \cap B $.
Q.7 Solve this question :
Prove that (a) the maximum number of nodes N on level i of a binary tree is $ 2^i $, $ i \ge 0 $ and (b) the maximum number of nodes in a binary tree of height h is $ 2^h - 1 $, $ h \ge 1 $.
Q.8 Solve this question :
Define Walks, Paths and Circuits related to a graph. Write down all possible (a) paths from $ v_1 $ to $ v_8 $, (b) circuits of G and (c) trails of length three in G from $ v_3 $ to $ v_5 $ of the graph shown in the figure below.

Q.9 Solve this question :
Show that if a and b are the only two odd degree vertices of a graph G, then a and b are connected in G. Prove that a connected graph G remains connected after removing an edge e from G if and only if e lie in some circuit in G.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option (any seven):
The set of all real numbers under the usual multiplication operation is not a group since
If $ R = \{(1, 2), (2, 3), (3, 3)\} $ be a relation defined on $ A = \{1, 2, 3\} $, then $ R \circ R $ is
Pick out the correct statement(s):
Let f and g be the functions defined by $ f(x) = 2x+3 $ and $ g(x) = 3x+2 $. Then the composition of f and g is
Among 200 people, 150 either swim or jog or both. If 85 swim and 60 swim and jog, then how many people jog?
If a graph is a tree, then
The relation R on the set of all integers, where $ (x, y) \in R $ if and only if $ xy \ge 1 $ is
How many functions are there from a set with three elements to a set with two elements?
Which one of the following is correct for any simple connected undirected graph with more than 2 vertices?
In an unweighted, undirected connected graph, the shortest path from a node S to every other node is computed most efficiently, in terms of time complexity, by
Q.2 Solve this question :
Define set. Let X be the universal set and $ S \subset X $, $ T \subset X $. Then prove
that:
(a) $ (S \cup T)^c = S^c \cap T^c $
(b) $ (S \cap T)^c = S^c \cup T^c $
Q.3 Solve both questions :
Define relations and function. What is equivalence relation?
Let A be the set of all people in India. If $ x, y \in A $, then let us say that $ (x,y) \in R $ if x and y have the same surname (i.e., last name). Then prove that R is an equivalence relation.
Q.4 Solve this question :
Define group, Abelian group and groupoid. Also define composition of functions. Let $ f: R \rightarrow \{x \in R: x \ge 0\} $ be given by $ f(x) = x^4 + x^2 + 6 $ and $ g: \{x \in R: x \ge 0\} \rightarrow R $ be given by $ g(x) = \sqrt{x} - 4 $. Then find $ (g \circ f)(x) $ and $ (f \circ g)(x) $.
Q.5 Solve both questions :
Suppose H and K are normal subgroups of G with $ H \cap K = \{1\} $. Show that $ xy = yx $ for all $ x \in H $ and $ y \in K $. Let $ I \in R $ be an ideal.
The radical $ \sqrt{I} = \{r \in R | rn \in I, n \in N\} $. Show that $ \sqrt{I} $ is an ideal.
Q.6 Solve this question :
Define commutative ring. Consider the set X, its power set $ P(X) = \{A | A \subset X\} $ is the set of all subsets of X. Show that the power set is a commutative ring under the following two operations $ A + B = (A - B) \cup (B - A) $ where $ \cup $ is set union and $ - $ is set difference, and $ AB = A \cap B $.
Q.7 Solve this question :
Prove that (a) the maximum number of nodes N on level i of a binary tree is $ 2^i $, $ i \ge 0 $ and (b) the maximum number of nodes in a binary tree of height h is $ 2^h - 1 $, $ h \ge 1 $.
Q.8 Solve this question :
Define Walks, Paths and Circuits related to a graph. Write down all possible (a) paths from $ v_1 $ to $ v_8 $, (b) circuits of G and (c) trails of length three in G from $ v_3 $ to $ v_5 $ of the graph shown in the figure below.

Q.9 Solve this question :
Show that if a and b are the only two odd degree vertices of a graph G, then a and b are connected in G. Prove that a connected graph G remains connected after removing an edge e from G if and only if e lie in some circuit in G.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Answer the following:
Choose the correct alternative from the following (any seven):
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Instructions:
- The marks are indicated in right-hand margin.
- There are TEN questions in this paper.
- Attempt any FIVE questions.
Questions
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following:
Answer the following: