At the spaceship the geiger for the definition of a number of hitting of the cosmic particles with the spaceship for some interval of time T is installed. The stream of cosmic particles is the Poisson...

At the spaceship the geiger for the definition of a number of hitting of the cosmic particles with the spaceship for some interval of time T is installed. The stream of cosmic particles is the Poisson flow (exponential arrivals) with the intensity λ, each particle is registered by the geiger with probability p. The geiger is switched on for the random time T which value is distributed under the exponential law with parameter µ. A random quantity ξ is a number of the registered particles. To find a distribution law of a random variable ξ.