Question

if A and B are two subsets of universal set U such that n(A) =10 ,n(B)=20 and n(u) = 60 n(A' subset B') = 40 , find n(A ∩ B)​

Answer 1

Answer:

n(A ∩B)= 10

Step-by-step explanation:

Given,

n(A) =10 ,

n(B)=20

n(u) = 60

n(A' subset B') = 40

n(A UB)= ?

we know,

n(A UB)= n(u) - n(A' subset B')

              = 60-40

               = 20

Now,

n(A ∩B)= n(A) + n(B) - n(A UB)

            =  10+20-20

            = 10

Hence, n(A ∩B)=10