jalen lost 12 pounds in the first 3 weeks of his diet. After this point , his weight loss slowed by half. If he lost a total of 84 pounds , how many weeks did it take him?

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%)