You are taking a course in chemistry this semester and the course has three exams that will determine your grade. The first exam counts as 20% of your grade, the second exam counts as 30% of your grade, and the third exam counts as 50% of your grade. Suppose you need a total of 90 weighted points on a 100 point scale in order to get an A in the class. If your first two exam scores are both 80, what score do you need to make on the third exam? Show your work here and how you would approach this problem. It is all right to round to the nearest whole number for your answer-but you must show your work or verbalize your reasoning to get credit for your answer.