What is the volume of a prism where the base is a 45-45-90 triangle with a leg of 5 in. when the height is 1.8 in.?

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%)