Question

two sets A and B are such that n(AuB) =21 and n(AnB) =7 , also n(A'nB') =9 find n(AnB)' .

Answer 1

Answer: 23

Step-by-step explanation:

As we know that n(A'∩B')=n(A∪B)'=U−n(A∪B)

Here

n(A∪B)=21 and n(A∩B)=7,

So using equation (1) we get, U−n(A∪B)=n(A'∩B')=9

or

U = 9+n(A∪B)=21+9=30

Now n(A∩B)'=U− n(A∩B)

=30−7

=23

Answer 2

Answer:

The value of n(AnB)' is 23

Step-by-step explanation:

As we know that n(A'∩B')=n(A∪B)'=U−n(A∪B)

Here

n(A∪B)=21 and n(A∩B)=7,

So using equation (1) we get, U−n(A∪B)=n(A'∩B')=9

or

U = 9+n(A∪B)=21+9=30

Now n(A∩B)'=U− n(A∩B)

=30−7

=23