Respuesta :

sadio0246

Answer:

solution:-We know that for any two finite sets A and B, n(A∪B)=n(A)+n(B)−n(A∩B).

Here, it is given that n(A)=20,n(B)=30 and n(A∪B)=40, therefore,

n(A∪B)=n(A)+n(B)−n(A∩B)

⇒40=20+30−n(A∩B)

⇒40=50−n(A∩B)

⇒n(A∩B)=50−40

⇒n(A∩B)=10

Hence, n(A∩B)=10

Step-by-step explanation:

hope it helps you friend ☺️

n(a) =40

n(b) =30

n(aπb) =20

n(aub)=x (let)

we know that

n(aub)=n(a)+n(b)–n(aπb)

x=40+30–20

x=70-20

x=50

n(aub)=50