So I looked up the word "Favorite" and this is the definition it gave:
"preferred before all others of the same kind"
So you can't have 24 favorite Friday shirts. But in that vein you can't have 7 either. So the only plausible answer if that you really meant Daily shirts. Since there are only 7 days of the week, you have one favorite shirt for each day of the week. Thus the answer is 7. You got it wrong. I got it right. lol