(i) Given : U={1,2,3,4,5,6,7,8,9}, A={1,2,3,4}
∵A′=U−A={1,2,3,4,5,6,7,8,9}−{1,2,3,4}
∴A′={5,6,7,8}
(ii) Given : U={1,2,3,4,5,6,7,8,9}, B={2,4,6,8}
∵B′=U−B={1,2,3,4,5,6,7,8,9}−{2,4,6,8}
∴B′={1,3,5,7,9}
(iii) Given : U={1,2,3,4,5,6,7,8,9},A={1,2,3,4} and C={3,4,5,6}
Step 1: Finding A∪C
∴A∪C={1,2,3,4,5,6}
Step 2: Finding (A∪C)′
(A∪C)′=U−(A∪C)′={1,2,3,4,5,6,7,8,9}−{1,2,3,4,5,6}
={7,8,9}
Final answer:
(A∪C)′={7,8,9}
(iv) Given : U={1,2,3,4,5,6,7,8,9},A={1,2,3,4} and B={2,4,6,8}
Step 1: Finding A∪B
∴A∪B={1,2,3,4,6,8}
Step 2: Finding (A∪B)′
(A∪B)′=U−(A∪B)={1,2,3,4,5,6,7,8,9}−{1,2,3,4,6,8}
={5,7,9}
Final answer:
(A∪B)′={5,7,9}
(v) Given: U={1,2,3,4,5,6,7,8,9}, A={1,2,3,4,}
Step 1: Finding complement of set A
A′=U−A={1,2,3,4,5,6,7,8,9}−{1,2,3,4}
={5,6,7,8,9}
Step 2: Finding coplement of A′
(A′)′=U−A′={1,2,3,4,5,6,7,8,9}−{5,6,7,8,9}
={1,2,3,4}
(A′)′=A
Final answer :
(A′)′={1,2,3,4}=A
(vi) Given: U={1,2,3,4,5,6,7,8,9},B={2,4,6,8} and C={3,4,5,6}
Step 1: Finding B−C.
B−C=B−(B∩C)
∵B∩C={2,4,6,8}∩{3,4,5,6}={4,6}
∴B−C={2,4,6,8}−{4,6}
={2,8}
Step 2: Finding complement of (B−C)
(B−C)′=U−(B−C)
={1,2,3,4,5,6,7,8,9}−{2,8}
={1,3,4,5,6,7,9}