For #2, I thought the "if the inflation drops" was another premises to the conclusion that follows. I see that its wrong but why?

Would the tiger argument be second because of the use of the word "can" or because it requires us to imply that tigers are mammals, or both (equally)?

All of my notes disappeared. I went to school the next day to find someone had one of my pages. Therefore, that person must have stole all my notes.