V is directly proportional to the cube of (r+1). When r= 1, V = 24.
Work out the value of 1 when r= 2.

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%)