Question

If A and B are sets such that n(A uu B)=36 n(A nn B)=16 and n(A-B)=15 then n(B)=...... ​

Answer 1

Answer: 21

Step-by-step explanation:

Given :

n(A uu B)=36

n(A nn B)=16

n(A-B)=15

Formulae :

n(A) = n(A-B) + n(A nn B)

n(A uu B) = n(A) + n(B) - n(A nn B)

               = [n(A-B) + n(A nn B) ] +n(B) - n(A nn B)

n(A uu B) = n(A-B)+n(B)

n(B) = n(A uu B)  - n(A-B)

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