Please solve

Truck arrivals at a terminal follow a Poisson process with an average of 2 trucks per hour. Consider the scenario where a truck has just arrived at the terminal. An employee wants to make sure he has enough time to take a break. Let T be the waiting time (in hours) before the next truck arrives. Determine the probability that this employee can take a 15-minute break, that is, calculate P (T> 0.25). Question: What is the probability that this employee is waiting more than an hour, knowing he's already waited 15 minutes