Question

If

   1,2,3,4,5,6,7,8 ,A 1,2,3,5,6   

and

B 2,3,4,7,8  

, find the following:

(i)

A' B 

(ii)

A B' 

(iii)

A B '​

Answer 1

Answer:

U={1,2,3,4,5,6,7,8,9}

A={2,4,6,8}

B={2,3,5,7}

(i) (A∪B)

′

={2,3,4,5,6,7,8}

′

={1,9}

A

′

∩B

′

={1,3,5,7,9}∩{1,4,6,8,9}={1,9}

∴(A∪B)

′

=A

′

∩B

′

(ii) (A∩B)

′

={2}

′

={1,3,4,5,6,7,8,9}

A

′

∪B

′

={1,3,5,7,9}∪{1,4,6,8,9}={1,3,4,5,6,7,8,9}

∴(A∩B)

′

=A

′

∪B

′