Suppose a job consists of n tasks, each of which takes time t seconds. Thus, if there are no failures, the sum over all compute nodes of the time taken to execute tasks at that node is nt. Suppose also that the probability of a task failing is p per job per second, and when a task fails, the overhead of management of the restart is such that it adds 10t seconds to the total execution time of the job. What is the total expected execution time of the job?