Van has $500 each semester to spend on books and sandwiches. Books are $100 each and sandwiches are $5 each. She has purchased 3 books this semester and 40 sandwiches. She tells you that her marginal utility from the next book is about 100 utils and the marginal utility from the next sandwich is about 15 utils. Has Van successfully maximized her utility this semester? How should she adjust her spending next semester?