Dex words at a dog adoption shelter. He has 4 large boxes of dog treats with 34 treats in each box and 3 small boxes with 28 treats in each box. How many bags of 20 treats can Dex mark from all the treats? HELP

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%)