If A = {x : x is a multiple of 4} and B = {x : x is a multiple of 6}, then A $$\cap$$ B consists of multiples of

Which of the following is not an equivalence relation in z?

If $$A = \{ x:{x^2} = 1\} $$ and $$B = \{ x:{x^4} = 1\} $$, then A $$\Delta$$ B is equal to

If n(A) = 1000, n(B) = 500, n(A $$\cap$$ B) $$\ge$$ 1 and n(A $$\cup$$ B) = P, then