At a multi screen movie theater two movies begin at 10 AM the first movie is shown every two hours the second movie is on every three hours what time will both movies be shown together again

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)