If A and B are subsets of the universal set U, then show that,
A⊂B⇔A∪B=B
If A and B are the sunsets of the universal set U, then show that
1. A is a subset of A union B
For universal set U, and sets A, B which are subsets of U, the following information is given.
n(U) = 36
n(A) = 12
n(B) = 10, n(A ∩ B) = 9
Then, the number of elements that are neither in A nor B is__