A small branch of a bank has the two tellers 1 and 2 . The service times at these tellers are independent and exponentially distributed with parameter \(\lambda=0.4\left[\mathrm{~min}^{-1}\right]\). When Pumeza arrives, the tellers are occupied by a customer each. So she has to wait. Teller 1 is the first to become free, and the service of Pumeza starts immediately. What is the probability that the service of Pumeza is finished sooner than the service of the customer at teller 2 ?