Could you help me deal with this problem

b) A student's best attempt for each of their six CML quizzes at the end of the semester in ECON1310 were 14/24, 21/27, 22/30, 14/26, 11/26, and 17/30. Their mid semester exam mark was 34/50. The best five out of six CML quizzes contribute 20% to the end of semester grade, the mid semester exam 25%, and the final exam 55%. By referring to the ECON1310 course profile, what minimum percentage mark would be required on the final exam for the student to receive: i) a grade of 4? ii) a grade of 5? If this same student had not attempted quiz 3 at all (and so received a score of 0 instead of 22/30), while the scores for the other five quizzes remained the same, what minimum percentage mark would be required on the final exam for the student to receive: iii) a grade of 4? iv) a grade of 5