Set U={1,2,3,4,5,6,7,8,9}A={x:x ∈N,30≤x2≤70} B={x:x is a prime number<10 }Find A′,B′,(A∪B),A′∩B′,(A−B)′
If U={x:x∈N}, A={x:x=2n,n∈N} and B={x:x is a prime number}, then A∩B is a set with cardinality ________.