Plane waves ( = 550 nm) impinge normally on a 5.00-mm diameter hole in an opaque screen

Plane waves (λ = 550 nm) impinge normally on a 5.00-mm diameter hole in an opaque screen (Σ). The diffraction pattern is observed on another screen (σ), which is slowly moved toward the aperture. At what distance from Σ will the near-field pattern (a system of bright and dark rings) show its first irradiance maximum on the central axis (at point-P)? At what distance will a minimum first appear at P? The first maximum is reached when the entire first Fresnel zone is exposed.