A contractor has two subcontractors for his excavation work. Experience shows that in 60% of the time, subcontractor A was available to do the job, whereas subcontractor B was available 80% of the time. (a) What is the probability that both subcontractors will be available to do the job? (b) If the contractor learned that subcontractor A is not available for the job, what is the probability that the other subcontractor will be available? (c) Suppose EA denotes the event that subcontractor A is available, and EB denotes that subcontractor B is available. (i) Are EA and EB statistically independent? (ii) Are EA and EB mutually exclusive? (iii) Are EA and EB collectively exhaustive?