Raymond places four colored blocks in a bag. The colors are red blue yellow and green without looking he reaches into the bag and pulls ne blockout
What is the probability that the block he pulls out will be yellow?

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%)