Question: Consider a parallel system consisting of two components denoted by 1 and 2. Such a system functions if and only if at least one of its components functions. Suppose that each component functions for a time period which is exponentially distributed with mean 1/λ independent of the other component. There is only one repairperson available to repair failed components, and repair times are independent exponential random variables with mean 1/µ. Find the long-run probability that the system works.