This little question used to mess with my head!!

I vividly remember a question like this appearing in my own Year 12 MM exam way-back-when. Gosh I wish I’d had someone explain it to me like this before I walked into that room!! Ugh.. they used to do my head in. I know now that the trick is to try and not over think it. Let me show you the straight-forward thought-process you can use yourself to ensure you get these questions right.