A professor has a weekly lecture class with a total of 72 students. The class has an equal number of men and women. The professor asks the teaching assistant to select students at random to participate in class demonstrations. Round your answers to two decimal places.

a. If two students are chosen, what are the chances that both are men?

b. If six students are chosen, how likely is it that the first four are women?

c. If three students are chosen, what is the probable occurrence of all being men?

d. If the ratio of women to men was two to one instead, what is the probability of three women being chosen?