Can y’all help me on question 20?!

Triangle xyz has vertices x(1,3), y(0,0)

Which is the solution to the inequality? 2 3/52 1/15 b< 3 2/15 b> 3 2/15

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%)