Question

One’s complement of a number x is y, then one’s complement of y is?

(a) y

(b) x

(c) x + y

(d) None of the mentioned

This question was addressed to me in class test.

The origin of the question is Number Theory in chapter Number Theory and Cryptography of Discrete Mathematics

Answer 1

Right option is (b) x

To explain I would say: Complement of Complement of number gives the same number.