Question

f n(A)=35,n(A∩B)=25 and n(A∪B)=50 then n(B)=? *

Answer 1

Answer:

n(AuB) = n(A) + n(B) - n(AnB)

Therefore, 50 = 35 + n(B) -25

Therefore, 50 = 10 + n(B)

Therefore, n(B) = 50 - 10

Therefore, n(B) = 40

Answer : n(B) = 10