
You wake up tomorrow, and what do you find in your bed? You. You wake up in bed next to yourself. You have no clue how he/you got there, but the fact still stands: you have a double! Everyone's secret dream come true! You both go through the next week without incident (well, "without incident" as much as you could with a double.)
Then everything goes wrong. After the week, you are in your home and turn around to find some scraggly old man wearing a cloak and leaning on a large wooden staff staring at you. Before you can say anything, he tells you that in 24 hours, the spell which has caused your double to appear will end, at which point, one of you will die. There will be a 50/50 chance as to which one dies, you or your double. Unless you kill your double. If you kill him, there will be a 15% chance that you will still die in 24 hours, but that's still a 35% improvement in survival chances. Before you can ask the old man anything, he disappears.
The question is two-fold:
1) The always fun: What would you do with your double during the first seven days?
2) The not-so fun: What would you do on the eighth day? Though be careful: Your double has the same choice that you have.