(dont ask) Can somebody help with this work?

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%)

Afarmer has decided to divide his land area in half in order to plant soy and corn. calculate the area of the entire area so he knows how much soil is needed. each bag of soil covers 20 square yards. how many bags should the farmer purchase? (4 points) 1 bag 2 bags 3 bags 4 bags

How many significant figures are there in the number 10.76?