the Marked price of an article is rupees 5000 after allowing some percent of discount and adding 10% bad the article is sold for rupees 4400 find the discount percent​

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%)