Let n(U) = 700, n(A) = 200, n(B) = 300 and n(A ∩ B) = 100,
Then n(Ac ∩ Bc =
400
600
300
200
n(Ac ∩ Bc = n[(A ∪ B)] = n(U) - n(A ∪ B)
= n(U) - [n(A) + n(B) - n(A ∩ B)]
= 700 - [200 + 300 - 100] = 300.
Let n(U) = 700, n(A) = 200, n(B) = 300 and n(A∩B)=100,
Then n(Ac∩Bc)=
If n(U)=700, n(A)=200, n(B)=300 and n(A∩B)=100, then n(A′∩B′)= ___.