Question: From past records, the director of a university’s computer labs knows that any one of the 12 PC’s in a particular lab is broken (not working) 10% of the time. Whether or not a PC breaks does not seem to depend on how much the PC is used, the weather, the time of day or any other factor he has investigated; PC’s seem to break at random. Eleven students enter the lab (which is currently empty) to work on papers due ‘immediately.’ What is the probability that all eleven students finding working PC’s so they can finish their papers?

a) (1 pt) Define the random variable for this problem.
b) (6 pts) Explain exactly how the random variable defines above is distributed.
c) (2 pts) Write out the probability question for this problem.
d) (6 pts) What is the probability that all eleven students finding working PC’s so they can finish their papers?