Maharashtra State Board
Chapter 1: Sets
Practice Set 1.1 Solutions
Q.1 Write the following sets in roster form.
(i) Set of even natural numbers
Answer: {2, 4, 6, 8, 10, …}
(ii) Set of even prime numbers from 1 to 50
Answer: {2}
(iii) Set of negative integers
Answer: {…, -5, -4, -3, -2, -1}
(iv) Seven basic sounds of a sargam (sur)
Answer: {Sa, Re, Ga, Ma, Pa, Dha, Ni}
Q.2 Write the following symbolic statements in words.
(i) 4/3 ∈ Q
Answer: 4/3 is a rational number.
(ii) –2 ∉ N
Answer: –2 is not a natural number.
(iii) P = {p | p is an odd number}
Answer: P is the set of all odd numbers.
Q.3 Write any two sets by listing method and by rule method.
Example 1:
Listing: A = {2, 4, 6, 8, 10}
Rule: A = {x | x is an even natural number ≤ 10}
Example 2:
Listing: B = {1, 3, 5, 7, 9}
Rule: B = {x | x is an odd natural number ≤ 10}
Q.4 Write the following sets using listing method.
(i) All months in the Indian solar year
Answer: {Chaitra, Vaishakh, Jyeshtha, Ashadha, Shravan, Bhadrapad, Ashwin, Kartik, Margashirsha, Paush, Magh, Phalgun}
(ii) Letters in the word "COMPLEMENT"
Answer: {C, O, M, P, L, E, N, T}
(iii) Set of human sensory organs
Answer: {Eyes, Ears, Nose, Tongue, Skin}
(iv) Set of prime numbers from 1 to 20
Answer: {2, 3, 5, 7, 11, 13, 17, 19}
(v) Names of continents of the world
Answer: {Asia, Africa, Europe, North America, South America, Australia, Antarctica}
Q.5 Write the following sets using rule method.
(i) A = {1, 4, 9, 16, 25, 36, 49, 64, 81, 100}
Answer: A = {x | x = n², n ∈ N, 1 ≤ n ≤ 10}
(ii) B = {6, 12, 18, 24, 30, 36, 42, 48}
Answer: B = {x | x = 6n, 1 ≤ n ≤ 8}
(iii) C = {S, M, I, L, E}
Answer: C = {x | x is a letter of the word "SMILE"}
(iv) D = {Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday}
Answer: D = {x | x is a day of the week}
(v) X = {a, e, t}
Answer: X = {x | x is a letter from the word "eat"}
Class 9 Maths Digest
- Practice Set 1.1 Class 9 Answers
- Practice Set 1.2 Class 9 Answers
- Practice Set 1.3 Class 9 Answers
- Practice Set 1.4 Class 9 Answers
- Problem Set 1 Class 9 Answers
- Practice Set 2.1 Class 9 Answers
- Practice Set 2.2 Class 9 Answers
- Practice Set 2.3 Class 9 Answers
- Practice Set 2.4 Class 9 Answers
- Practice Set 2.5 Class 9 Answers
- Problem Set 2 Class 9 Answers
