Question

Prove that if m and n are integers and nm is even, then m is even or n is even. What is the best approach here, direct proof, proof by contraposition, or proof by contradiction - why?

Answer 1

Answer:

Proof by contraposition

Step-by-step explanation:

If m and n both are odd, then mn is also odd.

m and n are integers which is not divisible by 2,

Therefore,

m×n is also not divisible by 2.

Which means mn is odd.