Bill, Mary, and Tom have coins with respective probabilities p1, p2, p3 of turning up heads. They toss their coins independently at the same times.(a) What is the probability it takes Mary more than n tosses to get a head?(b) What is the probability that the first person to get a head has to toss more than n times?(c) What is the probability that the first person to get a head has to toss exactly n times?(d) What is the probability that neither Bill nor Tom get a head before Mary?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.