Don’t let the fear of losing be greater than the excitement of winning. – Robert Kiyosaki

 NCERT EXERCISE 1.5
1. Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9} , A = { 1, 2, 3, 4}, B = { 2, 4, 6, 8 } and C = { 3, 4, 5, 6 }. Find
• (i) A′
• (ii) B′
• (A ∪ C)′
• (A ∪ B)′
• (v) (A′)′
• (B – C)′
1. If U = { a, b, c, d, e, f, g, h}, find the complements of the following sets:
• (i) A = {a, b, c}
• (ii) B = {d, e, f, g}
• C = {a, c, e, g}
• D = { f, g, h, a}
1. Taking the set of natural numbers as the universal set, write down the complements of the following sets:
• {x : x is an even natural number}
• { x : x is an odd natural number }
• {x : x is a positive multiple of 3}
• { x : x is a prime number }
• {x : x is a natural number divisible by 3 and 5}
• { x : x is a perfect square }
• { x : x is a perfect cube}
• { x : x + 5 = 8 }
• { x : 2x + 5 = 9}
• { x : x ≥ 7 }
• { x : x ∈ N and 2x + 1 > 10 }
1. If U = {1, 2, 3, 4, 5, 6, 7, 8, 9 }, A = {2, 4, 6, 8} and B = { 2, 3, 5, 7}. Verify that
• (i) (A ∪ B)′ = A′ ∩ B′
• (ii) (A ∩ B)′ = A′ ∪ B′
1. Draw appropriate Venn diagram for each of the following:
• (i) (A ∪ B)′,
• (ii) A′ ∩ B′,
(A ∩ B)′,
• A′ ∪ B′
1. Let U be the set of all triangles in a plane. If A is the set of all triangles with at least one angle different from 60°, what is A′?
1. Fill in the blanks to make each of the following a true statement:
• (i) A ∪ A′ = . . .
• (ii) f′ ∩ A = . . .
• A ∩ A′ = . . .
• U′ ∩ A = . . .