A local company has two identical lathe machines which are operated independently. A log is kept for each of the two machines and Table QII below shows the number of times that each machine has been operational in the last twelve months. Lathe Status A B Number of times working 780 650 Number of times not working 220 350 Table QII Draw the probability tree diagram and solve following questions Q1 If two machines are dependent what is the probability of either lathe working at the visit of supervisor? Q2 What is the probability that only one lathe would broke down? Q3 What is the probability that at least one lathe would have broken down