Quiz on Set Theory

If A={ , , , , , , ,0 1 2 3 4 5 6 7 8 9 10, , ,}, then insert appropriate symbol ∈ or ∉ in each of the following blank spaces. (i) 4 ... A (ii) −4 ... A (iii) 12 ... A are

• ∈ ∈ ∈, ,

• ∈ ∉ ∈, ,

• ∈ ∉ ∉, ,

• ∉ ∉ ∉, ,

The following set in Roster form is {x:xis positive integer and a divisor of 9}

• {1, 3, 9}

• {1, 3, 8}

• {9, 8, 27}

• None of these

The set of all natural numbers x such that 4 x + 9 < 50 in roster form is

• {1, 2, 4, 6, 8, 10}

• {1, 3, 5, 7, 9}

• {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

• None of the above

List of the elements of the following set {x : n := +1 2 and 13 ≤ n, where n ∈ N}, is

• {3, 10, 1, 5, 2, 3}

• {1, 2, 2, 3, 3, 10}

• {1, 2, 2, 5, 3, 5}

• {1, 2, 2, 5, 3, 10}

The set A = {14, 21, 28, 35, 42, ..., 98} in set-builder form is

• A = {x : n ∈ N and 7 ≤ n ≤ 15}

• A = {x : n ∈ N and 14 ≤ n ≤ 21}

• A = {x : n ∈ N and 31 ≤ n ≤ 13}

• A = {x : n ∈ N and 41 ≤ n ≤ 12}

If a set is denoted as A= φ, then number of elements in A is

• 0

• 1

• 2

• 3

A set B={ }5 is called

• singleton set

• empty set

• infinite set

• None of these

The set of months of a year is ...X... set. Here, X refers to

• empty

• finite

• infinite

• singleton

Let A= {x: x is a square of a natural number and x is less than 100} and B is a set of even natural numbers. The cardinality of A ∩ B is

• 4

• 5

• 9

• None of these

The set {1, 2, 3, ...} is ...Y... set. Here, Y refers to

• null

• finite

• infinite

• singleton