Yоu аre perfоrming а single mоlecule fluorescence experiment. You аre using a powerful microscope and are aiming to detect fluorescence signals from single molecules in solution. Given the concentration of fluorescent molecules in your sample and the focal volume of your microscope, you should detect on average the fluorescence of 2 molecules at any given time. What is the probability that you see 2 or more molecules at a specific time?