Mathematics
If A = {x ∈ W : 5 < x < 10}, B = {3, 4, 5, 6, 7} and C = {x = 2n ; n ∈ N and n ≤ 4}. Find :
(i) A ∩ (B ∪ C)
(ii) (B ∪ A) ∩ (B ∪ C)
(iii) B ∪ (A ∩ C)
(iv) (A ∩ B) ∪ (A ∩ C)
Name the sets which are equal.
Answer
A = {x ∈ W : 5 < x < 10}
A = {6, 7, 8, 9}
B = {3, 4, 5, 6, 7}
C = {x = 2n ; n ∈ N and n ≤ 4}
C = {2, 4, 6, 8}
(i) B ∪ C - contains all the elements in set B and C.
B ∪ C = {3, 4, 5, 6, 7} ∪ {2, 4, 6, 8}
B ∪ C = {2, 3, 4, 5, 6, 7, 8}
A ∩ (B ∪ C) - contains all the common elements in set A and (B ∪ C).
A ∩ (B ∪ C) = {6, 7, 8, 9} ∩ {2, 3, 4, 5, 6, 7, 8}
A ∩ (B ∪ C) = {6, 7, 8}
(ii) B ∪ A - contains all the elements in set B and A.
B ∪ A = {3, 4, 5, 6, 7} ∪ {6, 7, 8, 9}
B ∪ A = {3, 4, 5, 6, 7, 8, 9}
B ∪ C - contains all the elements in set B and C.
B ∪ C = {3, 4, 5, 6, 7} ∪ {2, 4, 6, 8}
B ∪ C = {2, 3, 4, 5, 6, 7, 8}
(B ∪ A) ∩ (B ∪ C) - contains all common elements in set (B ∪ A) and (B ∪ C).
(B ∪ A) ∩ (B ∪ C) = {3, 4, 5, 6, 7, 8, 9} ∩ {2, 3, 4, 5, 6, 7, 8}
(B ∪ A) ∩ (B ∪ C) = {3, 4, 5, 6, 7, 8}
(iii) A ∩ C - contains all the common elements in set A and C.
A ∩ C = {6, 7, 8, 9} ∩ {2, 4, 6, 8}
A ∩ C = {6, 8}
B ∪ (A ∩ C) - contains all the elements of B and (A ∩ C).
B ∪ (A ∩ C) = {3, 4, 5, 6, 7} ∪ {6, 8}
B ∪ (A ∩ C) = {3, 4, 5, 6, 7, 8}
(iv) A ∩ B - contains all the common elements in set A and B.
A ∩ B = {6, 7, 8, 9} ∩ {3, 4, 5, 6, 7}
A ∩ B = {6, 7}
A ∩ C - contains all the common elements in set A and C.
A ∩ C = {6, 7, 8, 9} ∩ {2, 4, 6, 8}
A ∩ C = {6, 8}
(A ∩ B) ∪ (A ∩ C) - contains all the elements of (A ∩ B) and (A ∩ C).
(A ∩ B) ∪ (A ∩ C) = {6, 7} ∪ {6, 8}
(A ∩ B) ∪ (A ∩ C) = {6, 7, 8}
As we can see that some sets are having same elements i.e, they are equal.
A ∩ (B ∪ C) = (A ∩ B) ∪ (A ∩ C) and B ∪ (A ∩ C) = (B ∪ A) ∩ (B ∪ C)
Related Questions
If A = {5, 6, 7, 8, 9}, B ={x : 3 < x < 8 and x ∈ W} and C = {x : x ≤ 5 and x ∈ N}. Find :
(i) A ∪ B and (A ∪ B) ∪ C
(ii) B ∪ C and A ∪ (B ∪ C)
(iii) A ∩ B and (A ∩ B) ∩ C
(iv) B ∩ C and A ∩ (B ∩ C)
Is (A ∪ B) u C = A ∪ (B ∪ C) ?
Is (A ∩ B) ∩ C = A ∩ (B ∩ C) ?
Given A = {0, 1, 2, 4, 5}, B = {0, 2, 4, 6, 8} and C = {0, 3, 6, 9}. Show that :
(i) A ∪ (B ∪ C) = (A ∪ B) ∪ C, i.e., the union of sets is associative.
(ii) A ∩ (B ∩ C) = (A ∩ B) ∩ C, i.e., the intersection of sets is associative.
If P = {factors of 36} and Q = {factors of 48} ; find :
(i) P ∪ Q
(ii) P ∩ Q
(iii) Q - P
(iv) P' ∩ Q
If A = {6, 7, 8, 9}, B = {4, 6, 8, 10} and C ={x : x ∈ N : 2 < x ≤ 7}; find :
(i) A - B
(ii) B - C
(iii) B - (A - C)
(iv) A - (B ∪ C)
(v) B - (A ∩ C)
(vi) B - B