Last updated at Jan. 27, 2020 by Teachoo

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Ex 1.4, 7 If A = {x: x is a natural number}, B ={x: x is an even natural number}, C = {x: x is an odd natural number} and D = {x: x is a prime number}, Find First, let’s write all the sets in roster form A = {x: x is a natural number} = {1, 2, 3, 4, 5 …} B = {x: x is an even natural number} = {2, 4, 6, 8 …} C = {x: x is an odd natural number} = {1, 3, 5, 7, 9 …} D = {x: x is a prime number} = {2, 3, 5, 7 …} Ex 1.4, 7 (i) A ∩ B A = {1, 2, 3, 4, 5 …} B = {2, 4, 6, 8 …} C = {1, 3, 5, 7, 9 …} D = {2, 3, 5, 7 , 11,13 …} A ∩ B = {1, 2, 3, 4, 5 …} ∩ {2, 4, 6, 8 …} = {2, 4, 6, 8, ..} = B Ex 1.4, 7 (ii) A ∩ C A = {1, 2, 3, 4, 5 …} B = {2, 4, 6, 8 …} C = {1, 3, 5, 7, 9 …} D = {2, 3, 5, 7 , 11,13 …} A ∩ C = {1, 2, 3, 4, 5 …} ∩ {1, 3, 5, 7, 9 …} = {1, 3, 5, 7, 9,…} = C Ex 1.4, 7 (iii) A ∩ D A = {1, 2, 3, 4, 5 …} B = {2, 4, 6, 8 …} C = {1, 3, 5, 7, 9 …} D = {2, 3, 5, 7 , 11,13 …} A ∩ D = {1, 2, 3, 4, 5 …} ∩ {2, 3, 5, 7 …} = {2, 3, 5, 7,…} = D Ex 1.4, 7 (iv) B ∩ C A = {1, 2, 3, 4, 5 …} B = {2, 4, 6, 8 …} C = {1, 3, 5, 7, 9 …} D = {2, 3, 5, 7 , 11,13 …} B ∩ C = {2, 4, 6, 8 …} ∩ {1, 3, 5, 7, 9 …} = { } = ∅ Ex 1.4, 7 (v) B ∩ D A = {1, 2, 3, 4, 5 …} B = {2, 4, 6, 8 …} C = {1, 3, 5, 7, 9 …} D = {2, 3, 5, 7 , 11,13 …} B ∩ D = {2, 4, 6, 8 …} ∩ {2, 3, 5, 7, …} = {2} Ex 1.4, 7 (vi) C ∩ D A = {1, 2, 3, 4, 5 …} B = {2, 4, 6, 8 …} C = {1, 3, 5, 7, 9 …} D = {2, 3, 5, 7 , 11,13 …} C ∩ D = {1, 3, 5, 7, 9 …} ∩ {2, 3, 5, 7 …} = {3, 5, 7, 11, 13, 17, 19…} = {x: x is odd prime number} Prime number = 2, 3, 5, 7, 11, 13,…. Odd prime number = 3, 5, 7, 11, 13,….

Ex 1.4

Ex 1.4, 1 (i)

Ex 1.4, 1 (ii)

Ex 1.4, 1 (iii)

Ex 1.4, 1 (iv) Important

Ex 1.4, 1 (v)

Ex 1.4, 2

Ex 1.4, 3 Important

Ex 1.4, 4 Important

Ex 1.4, 5 Important

Ex 1.4, 6

Ex 1.4, 7 You are here

Ex 1.4, 8 (i)

Ex 1.4, 8 (ii) Important

Ex 1.4, 8 (iii)

Ex 1.4, 9 Important Deleted for CBSE Board 2022 Exams

Ex 1.4, 10 (i) Deleted for CBSE Board 2022 Exams

Ex 1.4,10 (ii) Deleted for CBSE Board 2022 Exams

Ex 1.4, 10 (iii)

Ex 1.4, 11 Deleted for CBSE Board 2022 Exams

Ex 1.4, 12 Important

Chapter 1 Class 11 Sets (Term 1)

Serial order wise

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.