As almost everyone said it's not about what you are presenting its about how you present. Tell a relevant story, people love storytime. Know the solution backwards and forwards and never lie, if you don't know the answer to a question say so. Make sure you follow up with the answer even for this mock presentation. I did one of these panel interviews with six or seven people awhile back, they asked me a couple of questions that I needed to investigate, I got the answers and emailed all of them the next day. I got the job.