A: It depends. It depends on what exams the student took, how many they took and what scores they got in each. They are important in that they demonstrate that the student challenged themselves by taking AP courses and the exams. But at the same time, if the student self-reports AP scores of 3, that's doesn't help. Only a string of 4s and 5s, especially all 5s, would be impressive enough to set you apart from the rest of the applicant pool.
Please read the below article which addresses this subject perfectly:
