







Ex 1.4
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
Last updated at Jan. 27, 2020 by Teachoo
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,….