Question

If A and B are sets so that
n(A-B)=n(B-A)=n(AnB) and
n(AUB)=9 ,then n(P(A)) is​

Answer 1

Step-by-step explanation:

Answer :

Let us use some basic formulas,which could help us solve this question easily.

n(AUB)=n(A)+n(B)-n(AnB)

n(A-B)=n(A)-n(AnB)

Now,as per the question,

n(AUB)=36

n(AnB)=16

n(A-B)=15

Lets move back to the formulas.

n(AUB)=n(A)+n(B)-n(AnB) ---(1)

Substitute n(A-B) instead of n(A)-n(AnB) in the above formula (1).

Therefore,we get,

n(AUB)=n(A-B)+n(B) ------(2)

Substitute the given values in the above formula (2)

We get, 36=15+n(B)

Now, n(B)=36-15=21

Thank you :)

Answer 2

Answer:

the ans is option b) 20

Step-by-step explanation: