Your averages and values are the following:

Test={65, 90}
Quizzes={85, 70, 55}
Homework ={100, 70, 75, 90, 80, 50, 65}

What grade do you need on the final exam to earn a final grade average of at least 80 using the following grading system?

Test average 50%
Quiz average 15%
homework 10%
Final exam grade 25%