Assume that the devices fail independently and that the probabilities of failure are, respectively, P(C1fails)=0.25,P(C1works)=0.75P(C2fails)=0.25,P(C2works)=0.75P(C3fails)=0.4,P(C3works)=0.6P(C4fails)=0.45,P(C4works)=0.55 What is the probability that the network operates? Explain your assumptions