Question

if n(A) = 20, n(B) = 25, n(A ∩ B) = 10 then find n(AUB).

Answer 1

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

20+25-10=35

n(AUB)=35

Answer 2

answer -35. first you add the n(A)+n(B) and subtract the 10