# ML Aggarwal Sets Exe-5.1 Class 7 ICSE Maths Solutions

ML Aggarwal Sets Exe-5.1 Class 7 ICSE Maths Solutions. We Provide Step by Step Answer of Exe-5.1 Questions for Sets as council prescribe guideline for upcoming board exam. Visit official Website CISCE for detail information about ICSE Board Class-7.

## ML Aggarwal Sets Exe-5.1 Class 7 Maths Solutions

Board | ICSE |

Publications | Avichal Publishig Company (APC) |

Subject | Maths |

Class | 7th |

Chapter-5 | Sets |

Writer | ML Aggarwal |

Book Name | Understanding |

Topics | Solution of Exe-5.1 Questions |

Edition | 2023-2024 |

**Sets Exe-5.1**

ML Aggarwal Class 7 ICSE Maths Solutions

Page-107

**Question 1. State which of the following collections are set:**

(i) All states of India.

(ii) Four cities of India having more than one lac population.

(iii) All tall students of your school.

(iv) Four colours of a rainbow.

(v) All the beautiful flowers.

(vi) All clever people of Lucknow.

(vii) Last three days of a week.

(viii)All months of a year having at least 30 days.

**Answer:**

(i) It is a set.

(ii) It is not a set because the collection is not well defined.

(iii) It is not a set because the collection is not well defined.

(iv) It is not a set because the collection is not well defined.

(v) It is not a set because the collection is not well defined.

(vi) It is not a set because the collection is not well defined.

(vii) It is a set.

(viii) It is a set.

**Question- 2. Let A = {vowels of English alphabet}, then which of the following statements are true. In case a statement is incorrect, mention why.**

(i) c ∈ A

(ii) {a} ∈ A

(iii) a, i, u, ∈A

(iv) {a, u} ∉ A

(v) {a, i, u } ∈ A

(vi) a, b, ∈ A

**Answer:**

(i) As c is not a vowel, this statement is false.

(ii) This statement is false because {a} is a set and not an element.

(iii) This statement is true.

(iv) This statement is true as it is a set and not elements.

(v) This statement is false because {a, i, u} is a set and not an element.

(vi) This statement is false because b is not a vowel, so b ∉ A. And, a ∈ A.

**Question 3. Describe the following sets:**

(i) {a, b, c, d, e, f}

(ii) {2, 3, 5, 7, 11, 13, 17, 19}

(iii) {Friday, Saturday, Sunday}

(iv) {April, August, October}

**Answer:**

(i) The set of first six letters of the alphabet or {first six letters of alphabet}.

(ii) The set of prime numbers less than 20 or {prime numbers less than 20}.

(iii) The set of the last three days of a week or {the last three days of a week}.

(iv) The set of months of a year whose name begins with a vowel or {months of a year whose name begins with a vowel}.

**Question 4. Write the following sets in tabular form and also in set builder form:**

(i) The set of even whole numbers which lie between 10 and 50.

(ii) {months of a year having more than 30 days}

(iii) The set of single-digit whole numbers which are a perfect square.

(iv) The set of factors of 36.

**Answer:**

The given set can be written as:

(i) Tabular form: {12, 14, 16, 18, 20, ……. , 48}

Set builder form: {x : x = 2n, n ∈ N and 5 < n < 25}

(ii) Tabular form: {January, March, May, July, August, October, December)

Set builder form: {x | x is a month of a year having 31 days}

(iii) Tabular form: {0, 1, 4, 9}

Set builder form: {x | x is a perfect square of one digit number)

(iv) Tabular form: {1,2, 3, 4, 6, 9, 12, 18, 36}

Set builder form: {x | x is a factor of 36}

**Question- 5. Write the following sets in roster form and also in description form:**

(i) {x | x = 4n, n ∈ W and n < 5}

(ii) {x : x = n^{2}, n ∈ N and n < 8}

(iii) y : y = 2x – 1, x ∈ W and x < 5}

(iv) {x : x is a letter in word ULTIMATUM}

**Answer:**

(i) Whole numbers less than 5 are 0, 1, 2, 3, 4.

4n i.e., four times the above numbers are 0, 4, 8, 12, 16.

Thus, the given set can be written as:

{0, 4, 8, 12, 16} – Roster form

Or

{whole numbers which are divisible by 4 and less than 20} – Description form

(ii) Natural numbers less than 8 are 1, 2, 3, 4, 5, 6, 7

n^{2} i.e., squares of these numbers are 1, 4, 9, 16, 25, 36, 49

Thus, the given set can be written as:

{1,4, 9, 16, 25, 36, 49} – Roster form

Or

{squares of first seven natural numbers} – Description form

(iii) Whole numbers less than 5 are 0, 1, 2, 3, 4.

i.e. x = 0, 1, 2, 3, 4.

Given y = 2x – 1, putting x = 0, 1, 2, 3, 4, we get

y = 2 × 0 – 1, 2 × 1 – 1, 2 × 2 – 1, 2 × 3 – 1, 2 × 4 – 1

= 0 – 1, 2 – 1, 4 – 1, 6 – 1, 8 – 1

= -1, 1, 3, 5, 7

Thus, the given set can be written as:

{- 1, 1, 3, 5, 7} – Roster form

Or

{odd integers which lie between -2 and 8} – Description form

(iv) The given set can be written as:

{U, L, T, I, M, A}- Roster form [Write each element of the set once and only once] or

{letters in the word ULTIMATUM} – Description form)

(ML Aggarwal Sets Exe-5.1 Class 7 ICSE Maths Solutions)

**Question -6. Write the following sets in roster form:**

(i) {x | x ∈ N, 5 ≤ x < 10 }

(ii) {x | x = 6 p, p ∈ I and – 2 ≤ p ≤ 2}

(iii) {x | x = n^{2} – 1, n ∈ N and n < 5}

(iv) {x | x – 1 = 0}

(v) {x | x is a consonant in word NOTATION}

(vi) {x | x is a digit in the numeral 11056771}

**Answer:**

The given set can be written as:

(i) {5, 6, 7, 8, 9} – Roster form

(ii) Integers lie between -2 and 2 are -2, -1, 0, 1, 2, or p = -2, -1, 0, 1, 2

Given x = 6p i.e. putting p = -2, -1, 0, 1, 2, we get

x = 6 × (-2), 6 × (-1), 6 × 0, 6 × 1, 6 × 2

= -12, -6, 0, 6, 12

Thus, the given set can be written as {-12, -6, 0, 6, 12} in roster form

(iii) Natural numbers less than 5 are 1, 2, 3, 4

i.e., n = 1, 2, 3, 4

Given x = n^{2} – 1, putting n = 1, 2, 3, 4, we get

x = 1^{2} – 1, 2^{2} – 1, 3^{2} – 1, 4^{2} – 1 = 0, 3, 8, 15

Thus, the given set can be written as {0, 3, 8, 15} – Roster form

(iv) The given set can be written as {1} in roster form.

As, x – 1 = 0

⇒ x = 1

(v) The given set can be written as:

{N, T} in roster form

(vi) The given set can be written as:

{1, 0, 5, 6, 7} in roster form

**Question 7. Write the following sets in set builder form:**

(i) (1, 3, 5, 7, …….. 29}

(ii) {2, 3, 5, 7, 11, 13, 17, 19, 23, 29}

(iii) {1, 4, 9, 16, 25, ………}

(iv) {1/5, 1/6, 1/7, …… 1/20}

(v) {-16, -8, 0, 8, 16, 24, 32, 40}

(vi) {January, June, July}

**Answer:**

(i) {x | x is an odd natural number, x < 30}

(ii) {x | x is a prime number, x < 30}

(iii) The given numbers are perfect squares of natural numbers

{x | x = n^{2}, n ∈ N}

(iv) {x | x = 1/n, n ∈ N and 5 ≤ n ≤ 20}

(v) The given numbers are multiples of 8, lying between -16 and 40.

{x | x = 8p, p ∈ I and -2 ≤ p ≤ 5}

(vi) {x | x is a month of a year whose name begins with the letter ‘J’}

**Question 8. If V is the set of vowels in the word COMPETITION, write the given set in**

(i) description form

(ii) set builder form

(iii) roster form

**Answer:**

V =m {a set of vowels in the word COMPETITION} = {C,O,M,P,E,T,I,N}

(i) V = {Vowels in the word COMPETITION}

(ii) V = {x|x is vowel in the word COMPETITION }

(iii) V = {O, E, I}

— : End of ML Aggarwal Sets Exe-5.1 Class 7 ICSE Maths Solutions :–

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