I'm terrible at giving good advice, but I would say don't fake it. Yes, that is insane pressure to put on anyone. Yes, you should have been given at least 3-4 weeks to practice all those pieces. But for those who are taking drama seriously (like I do but not a high scale, just seriously when it comes to my drama classes in and out of school and now that I have to learn pieces for my Lamda exam) it is a very tough world out there.
My advice would be this: Try your best to perfect it as much as you can. Show your teacher what you are capable of in the strict time given to you, and if he's disappointed in your best efforts, then so be it.
As I said, I don't do well in advisory situations like this, but it's the best I've got. Good luck and enjoy it