There are 20 bicycles and 10 cars parked in the parking lot. Each bicycle had two wheels and each car had four wheels. How many wheels are there in total?
wheels

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%)