Two students need to pass the exam. The probability that the first student will pass it is 0.5, and the probability that the second student will pass it is 0.7. Find the expectation of passing the exam.
A committee is to consist of three members. If there are five men and six women available to serve on the committee, how many different committees can be formed?
Five math books and three literature books are on a shelf. How many ways can they be arranged if the math books are kept together and the literature books are kept together?
There are 13 patients in Dr. Ziglar's waiting room. Dr. Ziglar can see 8 patients before lunch. In how many different orders can Dr. Ziglar see 8 of the patients before lunch?
A bag contains 2 nickels, 9 dimes, and 8 quarters. If you draw 3 coins at random from the bag, without replacement, what is the probability that you will get a nickel (N), a quarter (Q), and a nickel (N), in that order?
A box contains 4 red balls, 2 white balls, and 6 black balls. Two balls are drawn at random from the box with replacement of the first before the second is drawn. What is the probability of getting a red (R) ball on the first draw and a white (W) ball on the second?