Question

A = {1,2,3,6}, B = {2,3,5,7} and U = {1,2,3,4,5,6,7,8,9,10}.
Then, A' ∩ B' =

• A. {2,3}
• B. {4,8,9,10}
• C. {1,2,3,5,6,7}
• D. {1,2,5,7}

Answer 1

The correct option is B {4,8,9,10}

Given:
A = {1,2,3,6}
B = {2,3,5,7}
U = {1,2,3,4,5,6,7,8,9,10}

A∪B = {1,2,3,5,6,7}

(A∪B)' = U – A∪B = {4,8,9,10}

According to De Morgan's first law,
(A∪B)' = A' ∩ B'

Thus, A' ∩ B' = {4,8,9,10}