For an environmental group, it is known that 75% of their door-to-door solicitations result in a donation of some kind. Find the probability that... (Hint: first determine what is a 'success' and what is a 'failure' based on what is being asked in each question)
a) ...of the next 5 visits, at least 3 will be refusals.
b) ...3 of the next 5 visits will result in donations.
c) ...the first refusal will occur on the fifth visit.
d) ...the second refusal will occur on the fifth visit.
e) ...the third donation will be made on the fifth visit.