In a multiple nodal network, each node is failed to connect to the server independently. The number of failures is measured per hour.

a) Let X be the number of failed nodes per hour and on averagethreenodes are failed per hour. What is the appropriate probability distribution to model X?

b) Using (a), find P(X>0).

c) Find P(X=1) per two hours.

d) What is the probability distribution of the time to arrival of the next failure?