In a physics experiment, a photographic plate is placed in f

In a physics experiment, a photographic plate is placed in front of a beam of radioactive particles, When a particle hits a plate, it leaves a trace on the plate. The number of such traces on a plate at the end of the experiment has a Poisson distribution. After a long series of experiments under similar conditions, the probability of a completely blank plate (no traces) was found to be 0.07.What should be the most frequently occurring number of traces? (Hint I am not asking for the mean here)