a mean average of 60 on seven exam is needed to pass a course. on her first exams, paula received grades 51, 72, 80, 62, 57, and 69

B) an average of 70 is needed to get a C in the course. is it possible for Paula to get a C? if so what grade must she receive on the seventh exam?

C) if her lowest grade of the exams already taken is to be dropped, what grade must she receive on her last exam to pass the course?

D)if her lowest grade of the exams already taken is to be dropped, what grade must she receive on her last exam to get a C in the course?

someone please help...