Suppose the probability of passing a driving test is 65%. (a) On a certain afternoon 15 people are tested. (i) What is the expected number of people who pass? (ii) What is the probability that exactly...

Suppose the probability of passing a driving test is 65%.

(a) On a certain afternoon 15 people are tested.

(i) What is the expected number of people who pass?

(ii) What is the probability that exactly 11 people pass?

(b) A certain teenager is determined to get a driving license no matter how many times he has to take the test until he finally passes.

(i) What is the probability that he passes on his third try?

(ii) What is the expected number of tries it takes to pass?