Question

Which of the arguments is not valid in proving sum of two odd number is not odd.

(a) 3 + 3 = 6, hence true for all

(b) 2n +1 + 2m +1 = 2(n+m+1) hence true for all

(c) All of the mentioned

(d) None of the mentioned

The question was asked in a job interview.

This question is from Types of Proofs topic in portion The Foundation: Logics and Proofs of Discrete Mathematics

Answer 1

Correct option is (a) 3 + 3 = 6, hence true for all

The explanation is: Some examples are not valid in proving results.