8. Probability. A. Suppose a bag of marbles contains 20 red, 10 white, and 5 blue, 3. Find the probability that a randomly selected marble is either white or blue. b. Find the probability that two randomly selected marbles are both red. B. if 10% of high school students fail their standardized test on the first attempt, find the probability that in a sample of 9 students all failed on their rst attempt. C. if 10% of high school students fail their standardized test on the first attempt, find the probability that in a sample of 9 students all passed on their first attempt. 9. Combinatorics. A. How many different random samples of size 25 can be selected from a population of 100? What is the probability of one particular random sample being selected? B. in how many ways can horses in a 10 horse race finish first, second, and third