your test score was a 75%. if there were 60 questions on the test how many questions did you get correct? how many more would you have needed to get right to receive an 80%?
If your test score was 75% and there were 60 questions on the test, you would have gotten 45 correct answers. In order to receive 80%, you would need to get three more correct that 45. That means you should have gotten 48 correct answers.