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Here's the problem:

It is almost the end of the grading period. I have 730 out of 880 points so far in my math class which means I currently have a B (83%). There are 90 points remaining before grades come out. My teacher rounds each student's score to the nearest percent. What is the fewest number of points I need to get and end up with a grade of


C (at least 70%)__________

B (at least 80%)__________

A (at least 90%)__________



Explain.