Which of the following are sets? Justify our answer.
(i) The collection of all months of a year beginning with the letter J.
(ii) The collection of ten most talented writers of India.
(iii) A team of eleven best-cricket batsmen of the world.
(iv) The collection of all boys in your class.
(v) The collection of all natural numbers less than 100.
(vi) A collection of novels written by the writer Munshi Prem Chand.
(vii) The collection of all even integers.
(viii) The collection of questions in this Chapter.
(ix) A collection of most dangerous animals of the world.
(i) The collection of all months of a year beginning with the letter J.
(ii) The collection of ten most talented writers of India.
(iii) A team of eleven best-cricket batsmen of the world.
(iv) The collection of all boys in your class.
(v) The collection of all natural numbers less than 100.
(vi) A collection of novels written by the writer Munshi Prem Chand.
(vii) The collection of all even integers.
(viii) The collection of questions in this Chapter.
(ix) A collection of most dangerous animals of the world.
Solution and Explanation
(i) The collection of all months of a year beginning with the letter J is a well-defined collection of objects
because one can definitely identify a month that belongs to this collection.
Hence, this collection is a set.
(ii) The collection of ten most talented writers of India is not a well-defined collection because the criteria for
determining a writer's talent may vary from person to person.
Hence, this collection is not a set.
(iii) A team of eleven best cricket batsmen of the world is not a well-defined collection because the criteria for
determining a batsman's talent may vary from person to person.
Hence, this collection is not a set.
(iv) The collection of all boys in your class is a well-defined collection because you can definitely identify a boy
who belongs to this collection.
Hence, this collection is a set.
(v) The collection of all natural numbers less than 100 is a well-defined collection because one can definitely
identify a number that belongs to this collection.
Hence, this collection is a set.
(vi) A collection of novels written by the writer Munshi Prem Chand is a well-defined collection because one can
definitely identify a book that belongs to this collection.
Hence, this collection is a set.
(vii) The collection of all even integers is a well-defined collection because one can definitely identify an even
integer that belongs to this collection.
Hence, this collection is a set.
(viii) The collection of questions in this chapter is a well-defined collection because one can definitely identify a
question that belongs to this chapter.
Hence, this collection is a set.
(ix) The collection of most dangerous animals of the world is not a well-defined collection because the criteria
for determining the dangerousness of an animal can vary from person to person.
Hence, this collection is not a set.
Top Questions on Sets and their Representations
- Write the following as intervals:
(i) {\(x: x ∈ R, -4 < x ≤ 6\)}
(ii) {\(x: x ∈ R, -12 < x < -10\)}
(iii) {\(x: x ∈ R, 0 ≤ x < 7\)}
(iv) {\(x: x ∈ R, 3 ≤ x ≤ 4\)}- CBSE Class XI
- Mathematics
- Sets and their Representations
- Match each of the set on the left in the roster form with the same set on the right described in set-builder
form:
(i) {1, 2, 3, 6} (a) {x: x is a prime number and a divisor of 6}
(ii) {2, 3} (b) {x: x is an odd natural number less than 10}
(iii) {M, A,T, H, E, I,C, S} (c) {x: x is natural number and divisor of 6}
(iv) {1, 3, 5, 7, 9} (d) {x: x is a letter of the word MATHEMATICS}- CBSE Class XI
- Mathematics
- Sets and their Representations
- Find the intersection of each pair of sets:
(i) X = {1, 3, 5} Y = {1, 2, 3}
(ii) A = {a, e, i, o, u} B = {a, b, c}
(iii) A = {x: x is a natural number and multiple of 3}
B = {x: x is a natural number less than 6}
(iv) A = {x: x is a natural number and \(1 < x ≤ 6\)}
B = {x: x is a natural number and \(6 < x < 10\)}
(v) A = {1, 2, 3}, B = \(\phi\)- CBSE Class XI
- Mathematics
- Sets and their Representations
- List all the elements of the following sets:
(i) A = {x: x is an odd natural number}
(ii) B = {x: x is an \(\frac{-1}{2} < x <\frac{ 9}{2}\) integer,}
(iii) C = {x: x is an \(x^2 ≤ 4 \) integer,
(iv) D = {x: x is a letter in the word “LOYAL“}
(v) E = {x: x is a month of a year not having 31 days}
(vi) F = {x: x is a consonant in the English alphabet which proceeds k}.- CBSE Class XI
- Mathematics
- Sets and their Representations
- Write the following sets in the set-builder form:
(i) (3, 6, 9, 12) (ii) {2, 4, 8, 16, 32}
(iii) {5, 25, 125, 625} (iv) {2, 4, 6 …}
(v) {1, 4, 9 … 100}- CBSE Class XI
- Mathematics
- Sets and their Representations
Questions Asked in CBSE Class XI exam
- Why did the narrator of the story want to forget the address?
- CBSE Class XI
- The address
- Give a brief description of the principles of the following techniques taking an example in each case.(a) Crystallisation (b) Distillation (c) Chromatography.
- CBSE Class XI
- Organic Chemistry- Some Basic Principles and Techniques
- Take one flower of the family Solanaceae and write its semi-technical description. Also draw their floral diagram.
- CBSE Class XI
- The Flower
- Using s, p, d notations, describe the orbital with the following quantum numbers.
- n=1, l=0
- n = 3, l=1
- n = 4, l =2
- n=4, l=3
- CBSE Class XI
- Developments Leading to the Bohr’s Model of Atom
- ‘The Address’ is a story of human predicament that follows war. Comment.
- CBSE Class XI
- The address
Concepts Used:
Sets
In mathematics, a set is a well-defined collection of objects. Sets are named and demonstrated using capital letter. In the set theory, the elements that a set comprises can be any sort of thing: people, numbers, letters of the alphabet, shapes, variables, etc.
Read More: Set Theory
Elements of a Set:
The items existing in a set are commonly known to be either elements or members of a set. The elements of a set are bounded in curly brackets separated by commas.
Read Also: Set Operation
Cardinal Number of a Set:
The cardinal number, cardinality, or order of a set indicates the total number of elements in the set.
Read More: Types of Sets