Proof that 8 is an even number by using contradiction technique

Question

My tutor gave an online assignment with this question: Proof that 8 is an even number by using contradiction technique

I've read about Proof by contradiction but I couldn't come up with any idea on how to start solving this.

Any help is much appreciated. Thanks.

Answer 1

Assume it is not even. Then it must be odd. If it is odd, it isn't divisible by $2$. But $8÷2=4$, so $8$ is divisible by $2$. This is in contradiction to the statement that it must be odd. Thus, it must be even.