# Discrete Mathematics Solved MCQs

1.

A. relation
B. function
C. set
D. proposition
2.

A. one
B. two
C. zero
D. three
3.

## The set O of odd positive integers less than 10 can be expressed by ___________

A. {1, 2, 3}
B. {1, 3, 5, 7, 9}
C. {1, 2, 5, 9}
D. {1, 5, 7, 9, 11}
Answer» B. {1, 3, 5, 7, 9}
4.

A. 10
B. 5
C. 3
D. 20
5.

## Which of the following two sets are equal?

A. a = {1, 2} and b = {1}
B. a = {1, 2} and b = {1, 2, 3}
C. a = {1, 2, 3} and b = {2, 1, 3}
D. a = {1, 2, 4} and b = {1, 2, 3}
Answer» C. a = {1, 2, 3} and b = {2, 1, 3}
6.

A. infinite
B. finite
C. subset
D. empty
7.

A. 8
B. 6
C. 7
D. 9
8.

## The members of the set S = {x x is the square of an integer and x < 100} is _________________.

A. {0, 2, 4, 5, 9, 58, 49, 56, 99, 12}
B. {0, 1, 4, 9, 16, 25, 36, 49, 64, 81}
C. {1, 4, 9, 16, 25, 36, 64, 81, 85, 99}
D. {0, 1, 4, 9, 16, 25, 36, 49, 64, 121}
Answer» B. {0, 1, 4, 9, 16, 25, 36, 49, 64, 81}
9.

## The union of the sets {1, 2, 5} and {1, 2, 6} is the set _______________.

A. {1, 2, 6, 1}
B. {1, 2, 5, 6}
C. {1, 2, 1, 2}
D. {1, 5, 6, 3}
Answer» B. {1, 2, 5, 6}
10.

A. {1, 2}
B. {5, 6}
C. {2, 5}
D. {1, 6}
11.

## Two sets are called disjoint if there _____________ is the empty set.

A. union complement
B. difference
C. intersection
D. complement
12.

## Which of the following two sets are disjoint?

A. {1, 3, 5} and {1, 3, 6}
B. {1, 2, 3} and {1, 2, 3}
C. {1, 3, 5} and {2, 3, 4}
D. {1, 3, 5} and {2, 4, 6}
Answer» D. {1, 3, 5} and {2, 4, 6}
13.

A. {1}
B. {5}
C. {3}
D. {2}
14.

A. a – b
B. u – a
C. a – u
D. b – a
15.

A. 1010100000
B. 1010101101
C. 1111111100
D. 1111101010
16.

A. A
B. null
C. U
D. B
17.

## If A = {a,b,{a,c}, ∅}, then A - {a,c} is

A. {a, b, ∅}
B. {b, {a, c}, ∅}
C. {c, {b, c}}
D. {b, {a, c}, ∅}
18.

## The set (A - B) – C is equal to the set

A. (a – b) ∩ c
B. (a∪ b) – c
C. (a – b) ∪ c
D. (a ∪ b) – c
Answer» D. (a ∪ b) – c
19.

A. 100
B. 120
C. 130
D. 140
20.

## Using Induction Principle if 13 = 1, 23 = 3 + 5, 33 = 7 + 9 + 11, then

A. 43= 15 + 17 + 19 + 21
B. 43= 11 + 13 + 15 + 17 + 19
C. 43 = 13 + 15 + 17 + 19
D. 43 = 13 + 15 + 17 + 19 + 21
Answer» C. 43 = 13 + 15 + 17 + 19
21.

## By mathematical Induction 2n> n3

A. for n ≥ 1
B. for n ≥ 4
C. for n ≥ 5
D. for n ≥ 10
Answer» D. for n ≥ 10
22.

## The symmetric difference A ⊕ B is the set

A. a – a ∩ b
B. (a∪ b) – (a∩ b)
C. (a – b) ∩ (b – a)
D. a ∪ (b – a)
Answer» B. (a∪ b) – (a∩ b)
23.

A. a ⊕ b
B. a ∪ b
C. a – b
D. a ∩ b
24.

A. a  b
B. a b
C. a  b
D. none of these