If A={5,6,7,8},B={1,3,5,7}, then the universal set is
If a universal set U={3,4,5,6,7,8,9,10,11,12}A={4,6,8,10,12}B={3,5,7,9,11} then (A∪B)′ is
Let U be the universal set containing 700 elements. If A, B are sub-sets of U such that n (A) = 200, n(B) =300 and n(A∩B)= 100. Then , n(A′∩B′)=