Use the following information to answer questions 39-41.
Ms. Martín uses a computer program to produce periodic progress reports for the 10 students in her Advanced Mathematics Ⅱ class. The report gives a student's scores on tests, quizzes, and homework assignments and the average of all 10 students' scores on each. The progress report shown below was produced near the end of the term for Richard Baldwin.
40. When Richard took the posttest, his score was 78. The increase from his pretest score to his posttest score was what whole percent of his pretest score?