PLEASE HELP, IT'S A INTERIM! Ms. Smith’s class will participate in an Algebra-Thon to raise money for a class trip. The Algebra-Thon workbook has 100 math problems. Students can raise money based on the number of math problems they answer correctly or by accepting a donation without regard to the number of math problems answered correctly.

As shown in the table, prizes are awarded to students who raise $50 or more. Benjamin, a student in the class, answers 80 math problems correctly. His grandmother pays $0.25 per correct answer. His uncle gives him a donation.

1. If Benjamin receives $45 from his grandmother and uncle, how much money does his uncle give him? Explain.