Such phenomena as diffraction and interference received their explanation only in the wave theory. However, one can observe the diffraction of individual photons by the slit. The light intensity is reduced so much that photons hit the slit one by one. The trajectory of the particle in each case can be unambiguously predicted, knowing the initial coordinate of the particle and its velocity. However, it is impossible to establish in advance what point the photon will hit after diffraction by the slit. We can only talk about the probability of a photon hitting the vicinity of a certain point. Experiment 1000 photons, shows the numerical distribution in the picture.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.