Question

if n(A) = 13 , n ( A U B ) = 28, n (A U B) = 7 then n(B)=​

Answer 1

Step-by-step explanation:

n(AUB)=n(A)+N(B)+n(ANB)

28=13+n(B)+7

28=20+n(b)

n(B)=8 OK friend

Answer 2

Answer:

15

Step-by-step explanation:

n(B)=28-13=15

or

n(B)=7-13=-6 (not possible)

so,n(B)=15