Final Exam period starts

Today, I have just finished my first final examination: Intermediate Macroeconomics. I think it is somehow easy except for one question about capital and investment. I thought about two ways of doing it during the exam and took the way that I think have more probabilty of being correct. However, after the exam, I went back to dormitory to check a similar question in my note, I found that the answers have used the two ways, which means, for some calculations, it used one way, but for another, it used another way. All the two ways are exclusive, which means only one way is right. I am really confused now as I didn't do well previously in my quiz, homework, and test. For me, if I want to get an A grade, I need to get 98/100 or more in final exam. I am quite unsure about my answer, which is the key determinant about whether or not I can get A. I hope that I am right. All right, since it is gone, I need to prepare for my next exam, whcih is statistical analysis on May 7th. Similarly, I need to get a high score to guarantee that I can get an A grade. So, keep fighting and good lock!!