TALLER INGLES 2 EJERCICIO

2. A two - runway (one runway for landing, one runway for taking off) airport is being designed for propeller - driven aircraft. The time to land an airplane is known to be exponentially distributed with a mean of 1-1/2 minutes. If airplane arrivals are assumed to occur at random, what arrival rate can be tolerated if the average wait in the sky is not to exceed 3 minutes?