Question

n(A)=15,n(B)=25,n(AuB)=5 find n(AnB)​

Answer 1

Answer:

n(A∪B)=n(A)+n(B)−n(A∩B)−−−−−−−(1)

Given n(A)=7

n(B)=9

n(A∪B)=14

Substituting in 1

14=7+9−n(A∩B)

⇒n(A∩B)=16−14=2

Answer 2

Answer:

n(A∪B)​ = 30

Step-by-step explanation:

Question :

n(A)=15, n(B)=25 , n(A∩B)=5 Find : n(A∪B)

Given :

n(A)=15

n(B)=25

n(A∩B)=5

To find:

n(A∪B)​

Solution :

n(A∪B)​ = n(A)​ + n(B)​ - ​n(A∩B)

            = 15 + 25 - 5

            = 40 - 5

            = 30

(I think there is a mistake in your question as n(A∪B) can never be less than n(A) and n(B) )