Please help me understand this!

Arc AB = _ Degrees

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%)

What are two numbers that have a sum of 15?

Walgreens sells both kleenex and nyquil. in a random sample of 5000 purchases, it was found that 1200 contained kleenex and 540 contained nyquil. these are not independent because sick people are more likely to buy both and healthy people more likely to buy neither. in looking into that, it was found that 360 purchases contained both. a. make a two-way table to display this information. fill in the table with the missing entries, and be sure your table has row and column totals. b. if we randomly select a purchase that contained kleenex, what is the probability it also contained nyquil? c. what percent of all purchases didn’t contain either product?