Question

16. 5 The following are true except (a) If every element of a set B is an element of a set A, then B is a subset of A. (b) A is a subset of B is denoted by A⊂B (c) Two sets A and B are equal if and only if A⊆B and B⊆A (d) Two sets A and B are equal if and only if A = -B and B = A
17. If A = { a + i b / a, b ϵ R }, then A is a set of ……… numbers (a) rational (b) natural (c) real (d) complex