If a 100-W lightbulb emits 3.0% of the input energy as visible light (average wavelength 550nm) uniformly

Question:

If a 100-W lightbulb emits 3.0% of the input energy as visible light (average wavelength 550nm) uniformly in all directions, estimate how many photons per second of visible light will strike the pupil (4.0 mm diameter) of the eye of an observer 1.0km away.