Of the 200 graduate students who were interviewed for a par time position at a call center, 110 had a bicycle, 25 had a master card and 130 had a mobile phone. 50 of them had both, a bicycle and a master card, 30 had both, a master card and a mobile phone and 60 had both, a bicycle and mobile phone and 10 had all three. How many candidates had none of the three?

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?