Solve the all given parts of following question:

Question: Laser light of wavelength 632.8 nm falls normally on a slit that is 0.0210mm wide. The transmitted light is viewed on a distant screen where the intensity at the center of the central bright fringe is 8.60W/m2.

Part A: Find the maximum number of totally dark fringes on the screen, assuming the screen is large enough to show them all.

Part B: At what angle does the dark fringe that is most distant from the center occur?

Part C: What is the maximum intensity of the bright fringe that occurs immediately before the dark fringe in part (b)? Approximate the angle at which this fringe occurs by assuming it is midway between the angles to the dark fringes on either side of it.

I want you to clarify the physics in this above question.