Let R be the rate at which customers are served in a queue. Suppose that R is exponential with pdf f(r) = 2e−2r on [0, ∞). Find the pdf of the waiting time per customer T = 1/R.

Let R be the rate at which customers are served in a queue. Suppose that R is
exponential with pdf f(r) = 2e−2r on [0, ∞).
Find the pdf of the waiting time per customer T = 1/R.