KCET 2019 Math Solved Paper

(B)
n(∪) = 100
n(A) = 50
n(B) = 60
n (A ∩ B) = 20
n (A ∪ B) = n (A) + n (B) - n (A ∩ B)
= 50 + 60 – 20
= 110 – 20
= 90
n (A' ∩ B') = n (A ∪ B)'
= n(∪) – n(A ∪ B)
= 100 – 90
= 10