Disjoint subsets a and b of a universal set u, except assume that n(u)=120, n(a)=45, and n(b)=50.

then n(a′∪b)=

 n (A'  U  B )  = 75

Step-by-step explanation:

Here, given :  n(U)=120, n(A)=45, and n(B)=50

As we know:

n (A ' U B)  =  n(A) − n (A∩B)   ... (1)

Here, n(A) = 45

So, n( A')  = n(U) - n(A)  = 120 - 45  = 75

⇒ n(A')  = 75

Now, as given A and B are disjoint sets.

⇒   n (A ∩ B)   = Ф

So, (A'  U  B )  = A'

So, n (A'  U  B )  =n( A') = 75

⇒  n (A'  U  B )  = 75

sorry i just need to anwers this to get points

step-by-step explanation:

2

step-by-step explanation: