Assume that there are k people in a room and we know that: • : = 5 with probability : • k = 10 with probability • k - 15 with probability a. What is the probability that at least two of them have been born in the same month? Assume that all months are equally likely. b. Given that we already know there are at least two people that celebrate their birthday in the same month, what is the probability that A = 10?

A math class consists of 25 students, 14 female and 11 male. Three students are selected at random to participate in a probability experiment. Compute the probability that three females are selected. Probability of first student being a female = (as a fraction) Probability of second student being a female = (as a fraction) Probability of third student being a female = (as a fraction) Probability that three females are selected = (as a decimal rounded to the nearest thousandth)

The month of September has thirty days. It is found on average that rain falls on twelve out of the thirty days in September. Assuming that it is equally likely that rain falls on any day in September, the probability that in any seven day period  the first two days will be wet and the next five days will be dry is: