A.) If a computer network has 60 switching nodes, in how many ways can 2 or 3 nodes fail?

B.) 2 copies of a code module are to be executed in parallel on identical processors organized into two communicating clusters A and B. Cluster A contains 8 processors and cluster B contains 4 processors. How many sets of processors can be used if cluster A has 2 failed processors and cluster B has 4 failed processors?