The 25/75 percentile for usc is 2040 – 2260. So your score of a 2040 lands you on the 25% for admitted students. Most of the students that are admitted below or at the 25 percentile have something very special about them. This may be that they have a perfect gpa, stellar extracurriculars, a first generation college student, or an underrepresented minority. You have not indicated that you have any of those things. If you have one of those hooks, you get helped in the admissions process and that increases your chances of getting into the school. Without those hooks however, it is not easy to get into the school seeing that the acceptance rate was 17.8% last year. Yes it is true that some people get in with scores below the average, but they are few and far between, so to increase your chances, do something to help your application stand out. This could be from founding a business related club to increasing your sat score 200 points or so. The sat and gpa are only two of the many factors in admission, so in order for people to make a fair assumption as to your chances, i would include the rest of your stats as well as everything else regarding your application.