"usually ellis rides his bicycle 5 4/5 miles a day. today he rode half his usual distance. how far did he ride. a: 2 2/5 b: 2 7/10 c: 2 9/10 or d: 3 4/10

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%)