In a large population, 60 % of the people have been vaccinated. If 4 people are randomly selected, what is the probability that AT LEAST ONE of them has been vaccinated

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Aflower has 26 chromosomes. to create a new flower, how many chromosomes would a sperm cell have? what is this process called? part 2: within a flower cell that has 26 chromosomes, how many chromosomes would a cell that is created within the stem of a flower as it grows, have? what is this process called?

Im so bad at fractions they are not my best math thing to work on