need help solving

An instructor who taught two sections of engineering statistics last term, the first with 25 students and the second with 30, decided to assign a term project. After all projects had been turned in, the instructor randomly ordered them before grading. Consider the first 15 graded projects. (a) What is the probability that exactly 10 of these are from the second section? (Round your answer to four decimal places.)

1

(b) What is the probability that at least 10 of these are from the second section? (Round your answer to four decimal places.)

2

(c) What is the probability that at least 10 of these are from the same section? (Round your answer to four decimal places.)

3

(d) What are the mean value and standard deviation of the number among these 15 that are from the second section? (Round your mean to the nearest whole number and your standard deviation to three decimal places.)

mean
standard deviation

(e) What are the mean value and standard deviation of the number of projects not among these first 15 that are from the second section? (Round your mean to the nearest whole number and your standard deviation to three decimal places.)

mean
standard deviation

problem 2 need help solving

A family decides to have children until it has three children of the same gender. Assuming P(B) = P(G) = 0.5, what is the pmf of X = the number of children in the family?

x	0	1	2	3	4	5	6
p(x)